In the tradition of runaway Kemper Open victories by rising stars, Larry Mize shot a four-under-par 68 in the third round at Congressional Country Club yesterday to forge a four-stroke lead over Corey Pavin.

If the syrupy-swinging Mize, currently fourth on the PGA Tour's Vardon Trophy list for low scoring, isn't the hottest young man on Tour, then it probably would be Pavin, who won two weeks ago at Colonial and stands third on the Vardon list. He matched Mize's 68.

To many, the leader boards make the Kemper look like the Mystery Man Open. Jim Nelford (68 yesterday) and Lennie Clements (69) are five shots behind Mize, with second-round leader George Archer (75) and Bill Glasson six strokes away. Seven strokes behind are three more fellows renowned within their own homes: Donnie Hammond, Jeff Sluman and Doug Tewell.

Kemper promoters may get a migraine from the twin headaches of little-known leaders and the chance of another rout. However, to Tour aficionados, a Mize-Pavin duel in today's final round could be a harbinger of many future meetings.

"I want to be like a horse pulling a buggy with blinders on," said Mize, who has a 10-under-par 206 total. "This is the first time for me as a sole leader (entering a final round). I know I can't just go out there and guide my way around. I have to keep on playing smart, aggressive golf."

"I know what a four-shot lead feels like. That's what I had at Colonial," said Pavin, who broke the rookie money record last year with $260,536. "If Mize shoots one or two under par, there's a 95 percent chance he'll win. But if I can play the front side two or three under, maybe I can put some pressure on him."

Mize, 26, a native of Augusta, Ga., has only one Tour victory in four seasons -- at the 1983 Danny Thomas Memphis Classic -- but he will seldom have a better chance than today.

Of the five players within six shots of Mize, only Archer and Pavin ever have won on Tour -- Pavin twice and Archer only once since 1976.

After bogeying the first hole, the 6-foot, 170-pound Mize ignored swirling, confusing winds to play the last 13 holes five under par with birdies at the 6th, 8th, 10th, 11th and 17th holes. At the 11th, he chipped in from 25 feet and, at the 17th, he drained a 40-footer. Of that last putt, Mize said, "Fortunately, the hole jumped in the way."

While Mize's smooth tempo has given him a distinctive persona on Tour, Pavin is just entering the sport's consciousness. "I had a first and two seconds last year," Pavin said, "but none of those tournaments was televised, so not many people knew about it."

In the last month, Pavin has had a victory, a fourth place and now another shot at contention, all with television's red light on him. "I like that," he said. "We're entertainers."

Mize actually enters the last round with the second-largest third-round lead in the six years of the Kemper at Congressional. When Craig Stadler won by seven and six strokes in 1981 and 1982, he took three- and two-shot leads into the final round. Greg Norman (73 -- 216 this trip) was the all-time front-runner with a seven-shot advantage last year.

Mize, whose forte is consistency, seems more suited to holding a lead than most. Composure and tenacity run through his personality.

"Could the wheels come off? That's something that could happen, but it really doesn't enter my mind . . . ," Mize said. "Everybody says I have good tempo and rhythm. I don't go at it real fast. I don't do everything that way, smooth -- but when I was growing up I wanted to have a big smooth swing like Gene Littler or Sam Snead."

Mize knew about those greats firsthand. Growing up in Augusta, he worked at the Masters for 10 years in a row, sometimes putting up numbers on the scoreboard above the third green. As a top junior golfer in a little town that worships the game, he could have found a way to play the famous Augusta National course.

But he wouldn't. Even as a child, his sights were set higher than that.

"I wanted to be invited to play it," he says.

Because he wouldn't take anything the easy way, because he worked on every phase of his golf game, eradicating weaknesses even more than he works on his strengths, Mize made himself an almost seamless player. On the Tour stats, he ranks no higher than 10th, but no worse than 33rd, in every basic category except driving distance, where he is only in the middle of the pack.

Any shot that can be mastered with hard work and a hatred of repeated mistakes is in Mize's bag.

Mize showed his ability to keep those wheels from wobbling right away yesterday. He, Archer and Barry Jaeckel all bogeyed that first into-the-wind hole. Archer, who had been distracted and annoyed by a clicking camera, also bogeyed the next two holes and never regained his momentum. Jaeckel went into a day-long muttering, head-shaking funk that didn't end until he sank a 40-foot birdie putt on the last hole for a 76.

Mize, by contrast, just started making pars. When he conked a 290-yard wind-aided drive at the 542-yard, pond-guarded sixth hole, he decided to gamble. "I don't take chances unless the odds are in my favor, but that time I thought it was worth it to go for it."

With a perfectly balanced pass, Mize lashed a three-wood shot 250 yards to a deep pin placement, then two-putted from 10 paces for the birdie that got him rolling.

While Mize, who played his college golf at Georgia Tech, was gaining seven strokes on fading leader Archer, the 25-year-old Pavin was keeping pace.

Pavin, a product of UCLA, made his birdies at the 6th, 7th, 10th, 12th and 15th holes with putts of 7, 20, 1, 12 and 15 feet while making bogey only at the rough 14th after a poor chip.

For Pavin, all of this is just a continuation of a two-year surprise. After failing to get his PGA Tour card at the 1982 qualifying school, he roamed the world winning tournaments from South Africa to Germany to France. He put $75,000 in his pocket and came on Tour in '84 with the hope of making the top 125 and staying exempt.

Suddenly, he almost won the Bob Hope Classic, then did win in Houston. Last year, he was 18th in money and now he stands eighth with $228,349. If he grabbed the $90,000 purse here, he'd suddenly be No. 2 to Curtis Strange.

Today, Mize will learn what it feels like to tee up a golf ball with $90,000 in your hip pocket and everybody trying to steal it.

There are some guys that doesn't bother. But not many.