After building a big lead in his 100-meter heat Saturday, the reigning world champion eased up a lot with about 30 meters left — so much that the rest of the field began to catch him. Gay was forced to accelerate again and he lunged across the finish line in fourth place, good enough to advance. RESULTS

"I'm OK," he said. "I just misjudged the white line."

Really? Even if there are several white markings across the rust-colored track down the stretch, it was hardly a veteran move from a man who has won the past two U.S. titles in the dash. He also completed a 100-200 double at the 2007 world championships.

Indeed, had he not recovered, an exit by Gay in the first round of qualifying would have been a major surprise at this 10-day meet to determine the American roster for the Beijing Games.

His time of 10.14 seconds tied for the 11th-fastest among the 30 starters in the 100.

The best heat was run by Walter Dix, the 2007 NCAA champion from Florida State, who clocked 9.96 seconds.

"I've still got some left in the tank," Dix said.

None of the top contenders failed to reach the quarterfinals, to be run later Saturday. Among those moving on were Wallace Spearmon, a former teammate of Gay's at Arkansas who won the bronze medal in the 200 at the 2007 world championships; and John Capel, who was handed a two-year suspension in 2006 after testing positive for marijuana.

The afternoon competition came under a searing sun, with the temperature at 95 degrees. Dix, for one, liked the conditions.

"It helped me right from the start," he said. "When I stepped on the field, I was already sweating. So that was a good thing."

The men's semifinals and final are Sunday, with the top three finishers making the Olympic team. The women's 100 semifinals and final were to come later Saturday, with a far more established field than the men.

Allyson Felix owns Olympic and world championship medals, and is seen by many as a possible star of the Beijing Games.

Lauryn Williams has her share of medals, too.

Torri Edwards won a world title.

And Marshevet Hooker, whose primary track accomplishments so far came in college, managed to put that entire trio on notice heading into the semifinals: She appears to be peaking at the trials.

She ran a wind-aided 10.76 seconds to win her 100-meter quarterfinal Friday, tying her with former world record-holder Ashford as the fifth-fastest woman in all conditions.

"I heard the time first," said Hooker, an NCAA champion at Texas. "I was like, 'Wow!'"

Then, though, she heard the wind speed: 3.4 meters per second, above the 2.0 that's allowed for a time to count as a personal best or official record.

Still, only world-record holder Florence Griffith-Joyner, Marion Jones, Christine Arron and Merlene Ottey ever have run faster, regardless of wind. That impressed the other women in what's considered a talented field, with more than a half-dozen legitimate contenders for the 100 berths on the Beijing Games roster.

"She was fast. Real fast," said Edwards, the 2003 world champion in the 100. "I hope she's tired."

Hooker also had the fastest time of the opening round Friday, a wind-aided 10.94.

Saturday's schedule at Hayward Field also included the conclusion of the heptathlon and the men's shot put final.