PEOPLE NOTICE SHAWN O'Sullivan's hands first. Soft, pale, almost feminine hands, those of a young teen-aged boy, perhaps. Hands hiding knuckles. Hands with smooth uncallused palms that, even when squeezed into fists, are no more fearsome than white lace gloves.

"I noticed you have such small hands," says the startled Toronto ad executive who, despite this discovery, is about to put O'Sullivan's hands in a TV commercial for his largest client.

"You ever see the size of a bullet?" the 23-year-old O'Sullivan snaps, flashing a fist and an exaggerated smirk reminiscent of Don Knotts as Deputy Barney Fife. The playful gesture ends the conversation, but deepens the confusing imagery: This guy is tough? A 1984 Olympic silver medalist? Canada's Mary Lou Retton? And the only prot,eg,e of former world champion boxer Sugar Ray Leonard and his legendary manager Michael Trainer?

Something's out of kilter -- and that's good. Because Shawn O'Sullivan breaks the stereotype: He's no mug who'd be doing time or washing cars if he weren't breaking noses. O'Sullivan looks like the boy next door, and he is. He's not from a slum. He went to college. He talks in a dialect widely spoken on North American cul-de-sacs.

"You have to break the stereotype of the fighter because people don't like boxing anymore," says Trainer. "They like boxers."

The TV-wrought world of boxing -- heavy on men who can throw a hard right, but light on those who can parry a soft question -- is forever trapped between middle-class fans and ghetto performers. That's why O'Sullivan is hot: The Middle-Class Avenger, the boxer from the 'burbs.

With his mother's help, the guy answers his own fan mail. He made an estimated $300,000 in his first year as a pro fighter, but still lives in the unfinished basement of his parents' home -- where he stores his Merrill Lynch statements in a toolbox he last used to help renovate a nearby convent.

"If you never get your feet off the ground," says O'Sullivan earnestly, "you don't have far to fall."

O'Sullivan is white, and in a sport where blacks regularly thrash whites before white audiences, that helps. But as orchestrated by Trainer, who took Leonard from an Olympic gold to a $45 million fortune, O'Sullivan's welterweight championship quest goes beyond the search for a Great White Hope, beyond even boxing. White America loved Sugar Ray Leonard, says Trainer, because whites no longer demand that their heroes be white -- only that they be respectable, that they seem like somebody you'd invite over for a barbecue. Racism is out, "The Cosby Show" is in.

It is an unpredictable effort, this making of a champion. Yet its intricate strategy -- from boxing to giving interviews to endorsing products -- tells much about modern athletes and athletics, and a great deal about the yearnings of those who watch. Even in a sport dominated by tough boys from tough streets, it helps to be a child of the suburbs, or at least to seem so.

O'Sullivan is at that place where ambition, talent and hucksterism are intertwining to change his life. He's determined, however, not to lose what Leonard and Trainer call his "decency." He'd better not: decency is his aura -- the aura fans will demand if he, like Leonard, is to be richly marketed someday.

There is only one larger truth: the Middle-Class Avenger must keep winning.

MARK (FASTHANDS) LASSIEN sits in the fourth row of folding chairs, his arms crossed tensely. He looks like a little Joe Frazier.

Before him in the ring, Sugar Ray's skin glistens with sweat. He skips rope, shadowboxes, smiles, rolls his hips, banters with the crowd. They still love The Sugar! He's in Vancouver at the ballroom of the Sandman Inn to spar with O'Sullivan, who in a few days will enter his seventh pro fight, this one against Lassien. The first day of sparring drew about 300 men dressed mostly in jeans or cords, T-shirts or sweatshirts. On this second day, after newspaper sports articles about the sparring, the noon crowd has changed: Women in red skirts and white blouses, men in blue blazers and yellow ties.

O'Sullivan climbs through the ropes: He's handsome, 5-10, 150 pounds, well-trimmed chestnut hair, prominent unwrinkled forehead, strong jaw neatly shaven, modest but friendly nod and smile and wave for the crowd. His translucent skin glistens less regally than Leonard's, however, and his footwork is more leaden, his demeanor more som- ber. But that's why Ray's here -- to teach O'Sullivan boxing and entertainment tricks only a master could know.

The fun begins and Leonard's hands drop mockingly to his sides -- before they rise instantaneously to pound O'Sullivan with a heavy right. O'Sullivan lands a right, a left, another left. Whoa! O'Sullivan ducks a sweeping left hook -- and the fans and Leonard laugh hungrily at the thought it might have landed. "Watch the hook!" Leonard yells, and, boom, pounds O'Sullivan with a left hook. O'Sullivan interrupts the lesson with a staggering left to Leonard's head, but Sugar Ray steals the show again, dropping theatrically to the canvas as if he is hurt, which signals, of course, that he is not. The crowd roars.

"They just playin'," says Lassien, his fingers covering his mouth, making his voice almost inaudible. He is 23, a black kid from the projects in Vinton, La., with an 18-2 pro record, a respected prospect. Smart, too. But all the hoopla around this fight has taken him aback -- the TV cameras, the reporters. And his idol, Sugar Ray Leonard, is training O'Sullivan! Lassien decides that if he can win this fight, maybe he will catch the eye of the great Sugar Ray.

The show goes on and Lassien huddles with his trainer, 55-year- old Amand Peck. He tells Lassien that O'Sullivan's hands are quicker than the boxing grapevine reported, but that he sometimes retreats from close punching with his body and head up, unprotected, rather than with his head tucked, his body in a curling crouch. That is Lassien's moment of opportunity.

Next to Leonard, O'Sullivan looks surprisingly slight. His shoulders seem as wide as his hips. His chest, biceps, particularly his stomach, lack muscle definition. As Leonard joked, "He looks like a little wet leaf." But after a 94-6 amateur record and six undefeated pro bouts, Lassien and Peck are not lulled by the choirboy physique. "Punchers are born," Peck says, "punchers aren't made."

When O'Sullivan throws a punch, for instance, the geometry of his body is almost perfect, as if an imaginary verticle line runs through its center from head to toe. Boxing folklore proclaims that such balance allows a fighter to put his weightplus his punching speed plus his strength behind a blow, giving it more force. In fact, the only thing that really counts is a punch's momentum -- its mass multiplied by its speed ("small hands are fast hands" is a boxing truism) divided by how long the punch lingers on an opponent's face.

Simple Newtonian physic Cleveland State University physicist Jearl Walker, who has studied the dynamics of punching. Balance and reflexive timing are important, Walker says, because a punch's maximum speed is reached when the arm is two to three inches from full extension. Landing before or after drains a blow's impact.

Lassien, his body a classic V-shape, looks stronger than O'Sullivan. But he can't punch worth a damn, never could. So he's known in the trade as a "boxer," throwing quick but less powerful punches as he weaves side-to-side, wearing down and frustrating opponents in the style of Muhammad Ali. "Cuties," the flashy defensive boxers are called. The style has worked: Lassien has never been knocked out in 95 amateur and 20 pro fights, has never visited, as they say, Dream Street.

O'Sullivan is a boxer-puncher: always on the offensive, stalking, pounding a man's body until the arms slip, leaving his head revealed. But O'Sullivan, criticized by boxing insiders for being weak defensively, spent the last year polishing his boxing: pressing his punching speed up to 720 blows to the heavy bag in three minutes; sliding his head back or slipping it sideways from punches; moving in close to throw flurries before tucking his head, curling his body, and jabbing in retreat.

As Peck noticed, O'Sullivan sometimes forgets to dip. He's still raw, a year or two from fighting Top 10 contenders -- if he gets that far.

After the sparring, Peck makes a nervous observation: O'Sullivan didn't sweat much. "Tiptop shape!" Peck says. "Tiptop shape!" That's ominous because Lassien isn't in tiptop shape, maybe 80 percent of top shape. Already Lassien regrets that he didn't train harder.

"He'd be world champ in six months," sighs Peck. "If he could get his mind right."

MIKE TRAINER is the Professor of Respectability.

He's a short, 44-year-old white man, a Silver Spring lawyer, respected and resented by old-line boxing promoters for his success with Leonard. Trainer hardly resembles his boxers: his gray and thinning hair is held in place with a pssst of Final Net, and he's prone to bright white slacks hitched high on his soft and thick middle and loose, casual shirts that he frequently tugs away from his body as hefty men do.

Just about anything Trainer needs to judge a man falls within the Protestant Ethic: Does he work hard? Is he honest? Polite? Persistent? Responsible? Law abiding? Toss in good looks, clear speech, brains and talent, and you've got . . . decency.

"I like decent people," Trainer says. He particularly likes to work with them: No worrying about a kid doing his daily workout, whether he's up all night chasing women, drugs or booze. What's more, a decent kid -- white or black -- doesn't have to look like someone he isn't to attract middle-class fans.

"It isn't race," says Trainer. Leonard was a poor black kid from Palmer Park, Md., and he was a decent kid, high on Trainer's respectability index. Plus handsome, smart, skilled and articulate -- qualities Trainer nurtured.

Leonard never endorsed products just for money or granted interviews just for publicity, but to expand his aura of decency into a larger- than-life image beyond the ring. Trainer had Leonard photographed not in boxing trunks, but in expensive suits. He never approved a Penthouse interview and it too three years to agree to a Playboy interview. Fearing tasteless jokes, Trainer refused to let Leonard host "Saturday Night Live." Even Leonard's famous Seven-Up ads with his son, Little Ray, were meant to carry a subliminal message: Leonard breaks the racist stereotype that black men abandon their kids. Building on Leonard's genuine decency, Trainer marketed him so that even a racist could say: "I'm not a racist. I like Sugar Ray." Before a fight, Trainer would even talk with Leonard about what Leonard, win or lose, might tell reporters after the bout.

"The interview after the fight," says Trainer, "can be as important as the fight."

CHRIS HEBB'S "Sports Page" show on CKVU-TV at 11 p.m. is one of Vancouver's most popular sportscasts. Hebb is tall and boyishly handsome, his style effusive. After the Leonard-O'Sullivan sparring, he interviews Las en, who fidgets and, again, talks almost inaudibly:

Hebb, effusively: 'They call you 'Fasthands,' why is that?"

Lassien, slowly and after hesitation: "Well, 'cause I got quick hands."

FROM HEBB'S interview with Shawn O'Sullivan:

Hebb: "So you have Mark Lassien . . . What do you know about this fighter?"

O'Sullivan: "One of his biggest pluses is his experience . . . He sports a record of 18 wins against two losses . . . He also touts a quarterfinalist position . . . in a very respectable boxing tournament held in the United States . . . That's really a feather in his cap . . . He'll hopefully test me in many ways."

SHAWN O'SULLIVAN was a shy kid who sat on his mother's lap at family gatherings until he was 12. He was the youngest of five boys, all of whom were taught to box by their dad. But when Shawn's father took him from their suburban home to Toronto's seedy Cabbagetown Youth Center, Peter Wylie, club founder and O'Sullivan's trainer today, realized the boy was a natural. Even unschooled at 15, O'Sullivan's balance was expert. His reaction time, hearing and peripheral vision were off the chart.

But Wylie had seen plenty of boys with God-given gifts come and go. It was O'Sullivan's willingness to forgo the excesses of adolescence, his willingness to take instruction, his discipline -- his score on Trainer's respectability index -- that made him stand out among standouts. O'Sullivan began dividing his time between homework and workouts. He has a girlfriend now, but didn't have his first date until age 19. After a few bouts, O'Sullivan was thrashing amateur boxers with three times his experience. In four years, he was amateur light middleweight champion of the world.

"All of a sudden, I was The Boxer," O'Sullivan says. ".. Everybody wanted to have The Boxer at their dinners and at their fundraisers and at their charities and on their TV shows . . . It was then that, naturally, you start thinking, 'Boy, maybe I can do commercials, too.'

O'Sullivan met Trainer through a mutual acquaintance and asked for advice after he was offered $100,000 to turn pro in 1981. Trainer gave his spiel: A fighter can either sign with a big-time boxing promoter who may take up to half the fighter's winnings in return for promotion, training and business management or hire his own manager, as Leonard hired Trainer, pay for his own training and promotion and be an independent businessman. A signing bonus is great if a boxer never makes it big, but if he battles to the multimillion-dollar strata, he'll lose a fortune to his promoters.

Mike Trainer swears he never planned to manage another boxer after Leonard, who had made him a millionaire. Trainer's fee, an estimated 10 percent of O'Sullivan's net, wasn't worth the trouble. Real money would come only if the kid made it to the top, which was always a long shot. But Trainer liked O'Sullivan -- and he had the itch to prove that Ray Leonard's phenomenal success wasn't just a fluke of Ray's talent, that Trainer's handling had something to do with it. "Wouldn't it be neat to try to do it again?"

Then Sugar Ray got hooked. Almost in passing, he'd promised O'Sullivan that he'd work with him occasionally if the kid ever went pro. "That was natural because Mike was handling him, too," Leonard says. But after he retired, Leonard also found he enjoyed jumping in the ring once in a while, enjoyed having fans turn out to adore him again. It gets in the blood. Leonard says he has no financial stake in O'Sullivan, that he spars with him for free, that he pays his own way to the fights.

"He's a different fighter when Ray is there," says Ralph Citro, a prominent boxing "cut man" who has worked O'Sullivan's corner several times. "It just seems to do something to the kid when Ray works with him a few days before the fight."

The workouts with O'Sullivan were well publicized, though, and Leonard heard the gossip: Sugar Ray was hyping Trainer's Great White Hope. "For some reason it was pickin', pickin' at me for a while," says Leonard. He finally decided, the hell with it! He was no racist. The kid had real talent. Helping felt good. And white or not, Leonard liked O'Sullivan.

"I helped a lot of guys and they don't appreciate it . . . ," Leonard says. "I used to talk to guys and tell 'em, 'Listen, buddy, you know, you move to the right and in doing so you gotta get that right hand up because you're subject to be hit by a left hook.' (They'd say,) 'Oh, I move to the right because I think I get a better position.' . . . Hey, man, I was champ twice! . . . I don't waste my time . . .

"Shawn is decent with a capital D. That's gonna help his career."

A LESS SUCCESSFUL boxer could sit in his room the night before a fight and privately spit into a glass to lose the last few pounds needed to make his 148- pound welterweight limit. Not Shawn O'Sullivan. About 35,000 people are watching the British Columbia Lions pro football team play the Toronto Argonauts -- and an O'Sullivan appearance will draw some of them to his fight. Besides, Labatt Brewing Co., the largest Canadian brewery and a big O'Sullivan sponsor, is also the Lions' biggest sponsor.

So in the stadium's VIP restaurant O'Sullivan's glass of grape Bubble Yum spit is discreetly wrapped in a brown cloth napkin. But by now, even the vaunted O'Sullivan politeness has worn thin under the commercial onslaught: The sparring, the interviews, the call-in shows, the visit to the horse races, Hebb's show, now the Lions.

Except for such events, O'Sullivan rarely leaves his room during fight week. He watches old movies on TV, reads P. G. Wodehouse, orders room service. He's a shy man and going out requires that he always be ready to sign autographs or cheerfully listen to a guy criticize his left jab. He rarely goes to athletic games or concerts anymore. When his favorite singer, Kenny Rogers, came to Toronto, however, he did ask for roped-off seats. He'd never done that before, and it made him uncomfortable.

Sugar Ray always told him a fighter was more entertainer than boxer, and O'Sullivan is learning the lesson. When O'Sullivan and Leonard came jogging into one sparring session, for instance, O'Sullivan noticed a little girl, maybe 2 years old, standing with her mother in the front row. He thought about stopping to hug her, but feared it would look sappy. He turned -- and Ray was hugging the girl. "I knew he'd do that!" O'Sullivan laughs.

Another lesson: Rock star Bryan Adams, a wiry young man with pockmarked face and greasy hair, dropped by the Sandman to watch the Leonard-O'Sullivan sparring while he was in Vancouver. He asked Trainer if he could meet Leonard. "I knew Ray wouldn't know the guy if he parked his car," says Trainer. Sure enough, Leonard hadn't heard of Adams or his platinum album, "Reckless." So Trainer and Leonard plotted a little theater:

Trainer, a few minutes later: "Ray, I've got somebody here I want you to meet . . . "

"Bryan!" Leonard interrupted, "I love your music!"

"I wouldn't say it's a necessary evil," O'Sullivan says of self-promotion. "I will say that if I didn't have to do it, I wouldn't miss it."

With his glass now half full, O'Sullivan is walked through a gantlet of interviews with radio and TV reporters covering the Lions game. He gives enthusiastic answers to the same old questions. Then a short, round stadium PR man with sweat rings under his arms pokes his head in: "We'll get your little fighter on." O'Sullivan turns away and for the first time reveals a rage that must serve him well in the ring.

"Little fighter?" he growls in the tight-lipped style of Clint Eastwood. "Little fighter! That guy needs a nail in his brain! Little fighter?"

Leonard refuses to leave his seat for the 30-second introduction of O'Sullivan to the crowd, so Leonard is introduced from the stands. The TV camera pans on three black men: They wave cooperatively, but none of them is Sugar Ray. "Who the hell knew?" jokes a man from Labatt's, although the painful metaphor is lost on him.

O'Sullivan finally escapes, but on the way out the door is told he's scheduled to do a football radio talk show after the game. He picks up a book of matches in the staircase and, outside, angrily flicks lighted matches in 20-foot arcs. Nobody speaks. "I don't want to do that show," he says coldly. "I don't know anything about football." There is a long silence.

"It's more about the power of the human spirit," is the wry reply of O'Sullivan's brother, Kevin. The tension lifts, as if little Shawn O'Sullivan is suddenly embarrassed at his angry self-absorption.

"I guess I'll do it," he says sheepishly, and he does.

IT WAS A RULE: A boxer can't make it big in Canada.

Fight fans were few, boxers mediocre, promoters small- time, the country Balkanized with intense regional loyalties. It was a rule -- until O'Sullivan's Olympic medal.

Trainer's strategy seems simple in retrospect: While O'Sullivan is learning the boxing skills needed for the jump from amateur to pro, stay in Canada: Make O'Sullivan Canada's contender.

So playing off his Olympic publicity, O'Sullivan fought across Canada for a year. Because Labatt's owns Canada's only cable sports TV network, O'Sullivan also became the only Canadian boxer with bouts regularly broadcast nationwide, again projecting his image as Canada's fighter. Now it's time for the jump to the big leagues: His first U.S. fight in scheduled for Nov. 16 in Reno.

Outside the ring, O'Sullivan also was sold as the All- Canadian boy. In September, his first national Canadian TV commercial aired for Swiss Chalet, a chain of moderately priced family restaurants. The ad shows O'Sullivan clowning with his mother about how she always made him eat right -- and how she took him to Swiss Chalet. Truth is Mrs. O'Sullivan did take Shawn to Swiss Chalet. That's the beauty of it: O'Sullivan is his image. And like Leonard's Seven-Up ads, the Swiss Chalet spot passed the Mike Trainer test: It's an ad for O'Sullivan -- a nation- wide announcement of his decency, the aura he needs to attract more fans and more lucrative endorsements.

There is only one greater truth: He must keep winning.

BOXING RINGS, like boxers, come in various styles. A fast ring, covered with hard foam matting, gives a fraction of advantage to a boxer like Mark Lassien, saving energy in his quick legs. A slow ring, covered with softer matting, donates its fraction of advantage to a slower boxer-puncher like O'Sullivan. The ring in the Vancouver Agrodome, where scenes for the fourth Rocky movie were shot recently, is fast as rings go, its plywood flooring covered with dense one-inch matting.

Only the canvas slows the Agrodome ring on fight night before 2,500 fans. Its center is chafed, cutting down on the friction between canvas and shoe. And rips on its rim keep the canvas from being pulled as tightly as it should be, as tight as a drum skin. But the old blue canvas reads "Labatt" in the middle -- while the ring's new, custom-made canvas reads "Gionco's Sports World." Purism aside, the old blue canvas (after Labatt's Blue beer) stays. But as it turns out, neither fractions of advantage nor commercialism will win or lose this fight.

Fearful he would tire too soon, Lassien, elegant in purple satin trunks, boxed less than O'Sullivan expected. Throwing the flurries he'd practiced so diligently, O'Sullivan, pale even next to his white satins, boxed more than Lassien expected. Lassien held his hands high to protect his head from O'Sullivan's power. O'Sullivan pounded his body: Kill the body and the head will die.

Lassien caught a couple of good shots to the head in the first round, and with respect, pedaled backward. O'Sullivan occasionally retreated with head high, but escaped on the pathway between Lassien's recognition and his reaction. As is often the case for men like Mark Lassien, the moment of opportunity was exactly that, a moment. Above the din Sugar Ray bellowed blow-by-blow instructions to O'Sullivan, which nagged at Lassien's confidence.

"Upper cut, Shawn! Upper cut! Upper cut! Right! Come on, try it again! Try it again! There you go! Upper cut, baby! Right there in front of you! Back to the body! Back to the body! Right hand! Back to the body! . . . Hands up! Let's go under! Let's go under! Let's go under! Hands up, Shawn! Come on, baby! There ya go! . . . "

Just then -- at 2 minutes, 11 seconds into the second round -- Mark (Fasthands) Lassien was dispatched to Dream Street for the first time in his life. He was, at that instant, thinking about throwing a left over O'Sullivan's next right. Also at that instant, O'Sullivan heard Leonard demanding he punch from body-to-head, body-to-head. A left to the body stopped Lassien's liquid movement for a millisecond: He never saw the right. When it landed on Lassien's left ear, O'Sullivan knew it was a good punch because pain shot through his top two knuckles.

The inertia wrenched Lassien's body 180 degrees to its right and turned his head sideways. Nearly parallel to the floor -- his left arm out etched, his right arm tucked neatly beneath him -- Lassien seemed for a moment asleep on a bed of air. Then, as A.J. Liebling wrote of Rocky Marciano's first knockout of Jersey Joe Walcott, he hit the floor "like flour out of a chute."

"That's all!" shouted Sugar Ray, although it was really just the beginning.