There was loud music, dancing, chest-bumping, tongue-wagging, finger-waving and mugging for the camera, and this was in the minutes just before the men's 100-meter final. After the impromptu party at the starting line, urged on by 56,700 spectators at the Olympic Stadium, eight men got to the work of running the fastest and closest 100 in Olympic history, a race that lived up to the wild prelude and crowned U.S. sprinter Justin Gatlin the world's fastest man.

As thousands of flashbulbs sparkled throughout the stadium, Gatlin, 22, jetted smoothly into the lead with long, powerful strides, running with an ease that belied his speed, his age and the pressure of the sport's marquee race.

Gatlin crossed the finish line in 9.85 seconds, .01 ahead of Portugal's Francis Obikwelu (9.86), who was .01 ahead of 2000 Olympic champion Maurice Greene (9.87). Shawn Crawford, Gatlin's training partner and close friend, finished fourth in 9.89 seconds -- a time that would have earned him a medal in every other Olympic 100 final ever contested.

Never have more than two men run under 9.9 seconds in the Olympic gold medal race.

"It means the world to me," Gatlin said. "This is the reason why I am here, to win the gold medal. This is what I train for. This is why I shovel snow off the North Carolina track. . . . I knew I had won when I crossed the finish line. I was just shocked my dream had come true."

A day after University of Miami student Lauryn Williams, 20, claimed the 100 silver in the women's final, Gatlin provided further evidence that a youth movement has overtaken a sport recently dominated by older, more experienced athletes such as Greene, 30, a former world record holder who, thanks to Gatlin, is now also a former Olympic champion.

Greene, however, rebuffed the suggestion that Sunday's result signaled a passing of the mantle.

"I don't think I've passed it just yet," he said with a huge grin. "I'm not done. Though he is up and coming I don't feel my time is past."

The fact that Gatlin topped Greene was, perhaps, less surprising than the fact that he topped Crawford, who often beats Gatlin in both races and one-liners. In every round of the 100 here, Crawford posted faster times, though he finished one-hundredth of a second behind Gatlin at the July Olympic trials.

As close as they have been on the track, they are even closer off. After the first round of the 100, Crawford waited for Gatlin to finish his heat. The pair then went from camera to camera, giving interviews that resembled stand-up comedy.

In one of Sunday's semifinals, Crawford took the lead and, about 10 meters from the finish, turned to Gatlin, who was just a step beside him, and taunted him as they coasted to the finish.

The pair concluded that semifinal with a chest-bump to celebrate Crawford's first place and Gatlin's second. And that's how they started Sunday's final. As dance music blared throughout the stadium, they bumped chests for the cameras and clowned around, admiring their antics on the giant scoreboard. Greene, meantime, swaggered with his tongue out, snarling. Obikwelu wiggled his hips. Ghana's Aziz Zakari skipped to the beat. Kim Collins of St. Kitts and Nevis laughed.

"That atmosphere out there," Greene said, "if you're not ready to run, you would have been ready tonight."

Said Crawford: "They were playing Greek music and people were dancing. I don't think there was any tension."

Gatlin had the slowest reaction time of anyone in the field, but he made up the ground quickly. He sprinted through the finish and then kept running, pausing only to put his hands on his hips, look up at the stands, and take in the crowd. Though Crawford sprinted over to offer Gatlin congratulatory hug, he quickly stepped aside.

For the first time in weeks, Gatlin, who finished .01 behind Greene at the Olympic trials, had the stage to himself.

Crawford, who got out relatively slowly and couldn't summon a strong finish, kneeled at the edge of the track, staring up at the scoreboard, watching replays of the race. The shiny gold bottoms of his track spikes, designed specifically for the Olympics, reflected the stadium lights.

"My race was terrible," Crawford said. "My start was terrible. But, hey, that happens. . . . I'm not too upset, I'm just happy my . . . teammate won the gold medal."

Gatlin, who won six NCAA titles by the end of his sophomore season at the University of Tennessee, moved to Raleigh, N.C. in 2002 to work with Trevor Graham, the former coach of five-time Olympic medal winner Marion Jones. Graham also coached Tim Montgomery, Michelle Collins, and Alvin Harrison, all of whom face lifetime bans for alleged drug violations.

Graham's Sprint Capitol group includes Crawford and LaTasha Colander, who finished eighth in the women's 100 final.

"I am a genuine, clean champion," Gatlin said. "I go out there every day and do what I have to do. I want to bring back positively to the sport. . . . I can run out there with a smile on my face."

Gatlin spent his boyhood years in Brooklyn, where he hurdled fire hydrants and jumped off the family television to simulate events he saw on television. He dedicated the race to his high school coach in Pensacola, Fla., who Gatlin said first convinced him he could become a world champion.

Gatlin, as it turns out, went a step farther.

"That was the start of things to come," Crawford, 26, said. "I know he's going to carry that title, Olympic gold medalist in the 100, he's going to carry that with honor and dignity."

U.S. sprinter Justin Gatlin celebrates his gold medal-winning time of 9.85 seconds in the 100 meters. "This is what I train for. This is why I shovel snow off the North Carolina track. . . . I was just shocked my dream had come true."From right, Justin Gatlin edges out the competition -- including Shawn Crawford (4th place), Portugal's Francis Obikwelu (2nd) and Maurice Greene (3rd).