Tyson Gay ran with desperation on his face today and only finished fifth in his semi-final, leaving Jamaican rivals Asafa Powell and Usain Bolt battling for gold in the Olympic 100-meter final.

Tense before the start, Gay was slow out of the blocks and never caught up. U.S. team-mate Darvis Patton convincingly dipped for the line and the world champion didn't, making the difference between four and five, between making the final in track's premier event and stunning disappointment.

"I did my best. I don't have any excuses," Gay said. "I'm pretty upset. When I get back to the village it's probably going to set in."

The result left the final everyone craved without one of its key players. The Olympics were Gay's first competition since straining his hamstring at the U.S. trials six weeks ago. It caught up with him in the third qualifying race in just over 36 hours.

He refused to blame it on his hamstring though.

"I'm healthy. My leg is a little sore, just from the rounds," Gay said.

It means Gay's only chance at Olympic medals will come in the relays. The triple gold medalist from last year's world championships didn't qualify for the 200 when he pulled up lame at the U.S. trials.

The difference could not have been bigger between Gay and Bolt. The world record holder was loose and relaxed before the race, ran controlled for 70 meters before slowing to a trot across the line. And his time was 9.85 seconds. In comparison, Gay ran 10.05. Powell, was in control throughout Gay's semi-final and went through in 9.91.