Walter Dix, right, edges out fellow sprinters, from left to right, Justin Gatlin, Ivory Williams and Michael Rodgers to win the 100-meter race final during the U.S. track and field championships in Eugene, Ore. Gatlin took second, Rodgers took third and Williams was disqualified and running under protest. (Rick Bowmer/RICK BOWMER/ASSOCIATED PRESS)

The biggest news Friday at the U.S. track and field championships came from what did not take place at Hayward Field: Tyson Gay, the second-fastest man in history, pulled out of the 100 meters because of a nagging injury and announced he would not compete in this weekend’s 200.

Gay’s surprising departure from the championships without even setting foot on the track ended hopes of an end-of-summer showdown with Jamaican Usain Bolt, the world-record holder in the 100 and 200, at the world championships in Daegu, South Korea.

Gay, the only man to beat Bolt in the last three years, might not face Bolt again until the 2012 Summer Games in London.

The task of trying to derail the world’s fastest man and his Jamaican counterparts will be left to 2004 Olympic champion Justin Gatlin, who held the world record briefly in 2006 before a four-year doping ban erased it from the record books; 2008 Olympic bronze medal winner Walter Dix; and Michael Rodgers, the ‘10 U.S. champion.

Gatlin finished second to Dix in a tight 100 final. Dix outleaned Gatlin at the tape to get the win in 9.94 seconds; Gatlin was clocked in 9.95 and Rodgers finished in 9.99. All three will compete in the 100 in Daegu.

Gatlin, who has maintained that he never knowingly consumed banned drugs but continues to be barred from meets in Europe, knelt down on the track and wept after the race, in his first U.S. championships since 2006. He said he let loose with four years of pent-up frustration, sadness and anger.

“Coming out here has been a joy,” he said. But “I wish I had the opportunity to race against Tyson. . . . I was really anticipating racing Tyson at his best. I wish him well, and I hope he gets well.”

In the women’s 100, Carmelita Jeter claimed the gold medal in a wind-aided time of 10.74 seconds (with a wind of 2.7 meters per second); Marshevet Myers finished second in 10.83 and Miki Barber got third in 10.96. Jeter, who last year became the second-fastest woman in history behind the late Florence Griffith-Joyner, will be a favorite for the gold medal in Daegu.

Gay’s withdrawal was announced before the start of the semifinal round Friday. His agent, Mark Wetmore, said in a statement that Gay had been unable to warm up because of a hip and adductor problem on his right side that has been bothering him for several months. Gay did not address reporters.

“We’re just going to focus on getting him healthy,” Wetmore said during a brief phone interview. “He’s been running with this . . . for three months. He’s not running the 200.”

Gay had run a respectable time of 10.01 seconds in his first-round heat Thursday, but he complained after the race of pain in the hip.

Gay could still be named to the 4 x 100 relay team for the world championships as a discretionary selection, and there was speculation initially that he would run the 200, where he would have been a heavy favorite to make the team.

Gay, however, might shut down for the summer; it is unclear when or whether he will race again. The world team roster will be submitted to the world governing body (IAAF) on Aug. 8.

“It’s a big blow,” Dix said about Gay’s absence. “Tyson at his best is definitely one of the top runners in the world, probably ever. For us not to have him, we’re going to have to step up.”

As Gay struggled with the injury, Gatlin has quietly put himself in position for Friday night’s surprise. Competing in a handful of minor races last summer, Gatlin failed to break 10 seconds, posting a host of sub-par times. But he moved late last year to Clermont, Fla., to train under coach Brooks Johnson, and thing improved.

Three weeks ago at the Prefontaine Classic, Gatlin went under 10 seconds for the first time in five years, and he got faster in each round here, going from 10.08 to a wind-aided 9.99 seconds to his time in the final.

Though Gatlin has been blackballed from major meets in Europe, he has been met with warmth and friendship from his competitors here.

“He’s blessed,” said Ivory Williams, a race favorite who was disqualified because of a false start. “He had the heart to be a winner. You see what he did today? Being out for four years and getting second, that’s unreal. I love him to death, and congrats.”

Gatlin said he intends to try to make up for Gay’s absence in Daegu, chasing a victory.

“I just have to prepare myself for the next nine weeks to train and run like I’m going to win a gold medal,” Gatlin said. “Whatever [time] is going to make me cross the finish line first is what I’m going to focus on.”