By The Associated Press

CARSON, Calif. – The young burst through to victory, and one of the greatest sprinters of the past decade pulled up lame on an emotional afternoon at the U.S. track and field championships Saturday.

Olympic gold medalist Justin Gatlin endured a slap in the face to win the 100 meters in a stiff head wind and Maurice Greene went down with a hamstring injury 30 meters from the finish.

“Maurice Greene got out on me very well,” Gatlin said. “When he pulled up he smacked me in the face with his hand. If I didn’t lean back slightly, it would have been a dead-on hit on my nose.”

Another winner of Olympic gold, Jeremy Wariner, surged ahead of close friend Darold Williamson to win an exceedingly fast 400.

The 21-year-old Texan won in 44.20 seconds, the fastest time in the world this year. Williamson, the NCAA champion and Wariner’s former Baylor teammate, was second in 44.62. Andrew Rock came on at the finish to edge 19-year-old LaShawn Merritt for third and the final spot on the U.S. team. Rock ran 44.70, Merritt 44.73.

Gatlin, who gained a reprieve after being disqualified for a false start in the first round Friday, battled the wind for a victory in 10.08. Shawn Crawford was second in 10.17 and Leonard Scott third in 10.18.

Greene, a month shy of his 31st birthday, was in contention but pulled up with an obvious left hamstring injury. He hopped on his right leg, then fell to the track. The three-time world 100 champion, 2000 gold medalist and 2004 Olympic bronze medalist had to be helped off the track, deprived of a shot at a fourth world crown.

“It’s not going to Helsinki,” said Greene, in tears after the race. “I wanted to get my world championship title back. That hurts the most.”

Greene gave a long hug to a sobbing Scott, his training partner.

“I taught him everything I know,” Greene said. Scott whispered, “I love you man.”

The usually boastful and smiling Greene was devastated.

“I felt I got off to a good start, and as I started accelerating, I felt my hamstring pop,” Greene said. “You can never tell how bad it is until the next day. I knew I was in a good position. I felt I could have won it.”

Wariner won, but knew he could have run faster.

“I stumbled out of the blocks, and that probably knocked a couple of tenths off,” he said.

The speed events were center stage on Day 3 of the four-day competition in sunny, breezy conditions at Home Depot Center. The top three finishers in each event make the U.S. team for the world championships Aug. 6-14 in Helsinki, providing they meet the world qualifying standards.

It was a big day for the emerging young stars of the sport.

Sanya Richards, just 20, led three runners under 50 seconds in the women’s 400. Richards’ winning time of 49.28 was a meet record and the world’s fastest time this year by more than a half-second. She was followed by Dee Dee Trotter at 49.88 and Monique Henderson at 49.96.

“With three women under 50, what more can you ask for?” Richards said. “With the three of us being only 20, 21 (actually Trotter and Henderson are 22), the sky is the limit.”

Me’Lisa Barber, also running into a head wind, cruised ahead of the competition to win the women’s 100 in 11.10. Conspicuously absent from the women’s 100 was Marion Jones. Once the charismatic star of U.S. track, Jones walked off the track at the starting blocks before Friday’s first round. Her agent Charles Wells said she had a hip flexor injury.

Barber, 24, switched to coach Trevor Graham last year and has bolted from relative obscurity to international prominence this year. Before this season, she had not run a 100 since 2002. Injury prone, she had concentrated on the 400 with little success.

Graham also coaches Gatlin and Crawford and is the former coach of Jones.

Muna Lee was second in 11.28, with Olympic silver medalist Lauryn Williams barely making the U.S. team in third at 11.29. Barber had run a sizzling, wind-aided 10.87 in the semifinals.

Lashinda Demus, 22, won the 400 hurdles in a personal-best 53.35, second-fastest in the world this year.

“I know what I’m capable of, and that’s medaling at the worlds,” Demus said.

Alan Webb, 22, repeated as 1,500 champion, edging his training partner Christopher Lukezic. Webb ran 3:41.97, Lukezic 3:42.06.

Tyson Gay was the leading qualifier in the men’s 200 at 20.38. Rachelle Smith was the fastest 200 qualifier in 22.53.

One old-timer came through.

Stacy Dragila won her 17th U.S. pole vault championship, ninth outdoors, clearing 14 feet, 7 inches. The 34-year-old Dragila, the 2000 Olympic gold medalist, was more than a foot below her career best of 15-10 set last year. Recovering from an ankle injury, Dragila missed two tries at her first height of 13-9 .

“I was just happy I got off the ground and made some bars,” she said. “I relied on my past experience.”

Crawford ran 9.99 in his 100 semifinal heat. Only new world record holder Asafa Powell of Jamaica has run faster.

Gatlin almost was an early casualty in the 100. He was disqualified by a false start Friday, but filed a protest and was reinstated when meet referee Ed Gorman ruled that motion by the runner next to him could have caused Gatlin’s early start.

Early Saturday, Teresa Vaill shattered the American record by more than five minutes in the 20-kilometer walk, winning in 1:33.28. The old mark was 1:38.19, set by Danielle Kirk in 2000.

AP-ES-06-25-05 2057EDT