Sugar Ray Leonard will knock out Roberto Duran before the 11th round. Leonard is the bigger man, three inches taller. He is the faster man, both with his feet and hands. He is the stronger. Leonard, consequently, hits harder than Duran, both with the jab and the hook, and he will hit the little man the way little men never hit Duran. Too often, we call Leonard the artist, forgetting he has a fighter's necessary cruetly and power. What Duran, the alley fighter, gives Friday night, Leonard will return.

What we will see at the Olympic Stadium here Friday night is the certification of Ray Leonard as a great fighter, for this welter-weight championship fight will be a test of Leonard's will as well as his ability. "Leonard, he is IBM," said Rubin Blades, a friend of Duran, "and Roberto, he counts on his fingers." The image suggests a certain corporate softness to Leonard, a weakness to be exploited by a noble savage.

Not so.

Men have run from Duran. Of his 69 victories in 70 fights, 55 have been by knockouts, 25 of those in the first two rounds. All but one of those early round victims were lightweights, however, and Duran has not been fearsome in two years with the welter-weights. Leonard will not run. He will move, certainly, move to his right, but only to set up Duran for that powerful jab. And when the time comes, Leonard will stand and fight, ending it with a right hand.

Knowing all this, dear reader, you might stay at home and thereby take food from the mouth of little Ray Charles Leonard Jr. So the typist quickly adds that his record in fight predictions is not flawless. Somehow Jimmy Ellis did not defeat Joe Frazier as advertised, and neither did Muhammad Ali dance circles around the same Frazier the first time they fought.

Picking the fights is a chancy propositon, as Chuck Wepner has testified. Wepner, the Bayonne Bleeder, was going in with Ali in the mid-7os. Although his face carried 250 stitches -- "Ya gotta remember, 75 of them are from Liston," Wepner explained -- the butcher from Bayonne, N.J., was confident of victory over a dissipating Ali.

The night before the fight, Wepner gave his wife the gift of a nice blue nightgown and told her to save it for after the fight. "When you wear this thing," he said, "You'll be sleeping with the heavyweight champion of the world."

Wepner tells this story himself. "So when I get out of the hospital after the fight and I go back to the room, my wife is there in the blue nightgown. She says, 'well, do I go to his room or does he come to mine?'"

If the people of Montreal had their way, they would all go to Roberto Duran's room Friday night. He is this city's favorite in what is being called "le face a face histortique." Of the hoped-for 50,000 customers at Olympic Stadium, the majority are expected to side with Duran, the smiling Latin, against the American hero who won an Olympic gold medal here.

"Montrealers love a show more than anything else," wrote Montreal Gazette columnist Tim Burke today, "and Duran has ben giving them one from the day he set foot in the town.His swashbucking manner and his clowning and his boisterous Latin imagination. 'Duran est beaucoup de fun.'"

In contrast, Leonard, while unfailingly polite and correct, has been more workmanlike, even to the point of virtually ignoring Duran's provocations during a public weigh-in Wednesday. "Two more days, two more days," Duran shouted at Leonard in English, turning the back of his upraised left fist to him and acting as if he wanted to climb a riot fence to get at Mr. IBM.

In response, Leonard blew him a kiss.

Nothing short of a Francis Ford Coppola production should be compared to the scene around an Ali fight -- recreating such a scene might cost Coppola $50 million, come to think of it -- but that one inevitably thinks in those terms.

Lenard-Duran, next to any Ali fight, is a dud, scene-wise.

Flip is here. Flip is an intrepreneur of the evening. One suspects, on seeing this tall and handsome fellow in his thousand-dollar cowboy boots and striking velvet hats, that Flip, if asked, could deliver to your room the congressman of your choice.

But Flip is disconsolate this week.

"Action," he said, "is among the missing here."

Women of sliding moral values, men who need native bearers for their jewerly boxes and the universe of sociologists, religiologists and suffocating sycophants -- all of the circus following Ali -- are among the missing here.

"That's because Ray is genuine," said Angelo Dundee, Ali's trainer and Leonard's manager, "What you see, a nice, sweet kid, is what you get. No 'Ugly Bears,' no 'Washerwoman.'"

The Bear was Ali's name for Sonny Liston, the Washington was George Chuvalo.

"Ray is home cookin'," Dundee said.

Mick Jagger came to an Ali fight in Yankee Stadium.

Ray Leonard can't get Woody Allen.

Woody Allen, Frank Sinatra, Jean-Paul Belmondo, Blondie and another dozen big-name celebrites have been advertised as coming to the fight. The fight promoters, knowing Montrealers love a good show, have used those names in radio advertisements."These great names will be able to say, 'I WAS THERE!' Will you?" the commercials shout.

At it happens, those great names won't be here.

The celebrity columnist of the Montreal Gazette tracked them all down. None was certain of attending and most said they had no idea there was a fight. Frank Sinatra, for one, is working fight night at Carnegie Hall in New York.

Besides the great names, the Little names won't be there either. As of Wednesday, only about 30,000 tickets had been sold. Bob Arum, the New York promoter who is handling only the closed-circuit TV end of this fight, says the Montreal promoters have botched the live gate by charging too much for tickets and not marketing the event in the United States.

The cheapest seat was $20. The cheapest seat still available is $50.

In serious escalation, Arum has upgraded Leonard-Duran from "fight of the decade" to "dream fight of the century." Maybe he realized the decade is only 170 days old. In any case, he says closed-circuit seats are selling in unprecedented numbers and the production is now up from 310 theater locations to almost 400. He uses the number $30 million as an optimistic guess at TV income.

And who not? Friday night, we see another Sugar Ray.

In 1945, a fighter named George Costner, who called himself Sugar Costner, stepped into the ring against a man named Walker Smith, who called himself Sugar Ray Robinson.

"There's only room for one Sugar," Robinson said to Costner during the prefight instructions. He was angry.

Costner was knocked out in one round.

Five years later, they were matched again.

"I told you," Sugar Ray Robinson said, "there's only one Sugar."

Another first-round knockout.

Now, 30 years later, Ray Leonard will show there is room for two Sugars.