On the eve of the race, American champion Shawn Crawford was exuding how Bolt could clinch a second world record by slicing .02 seconds off the mark the Jamaican already owns.

"I really think 19.28," Crawford said.

His own ambition? 19.51 seconds.

"I'll be happy with that," Crawford said Tuesday after he and Bolt reached the final.

But is there really no way to beat the Jamaican giant?

"If I can trip him without getting caught," Crawford joked. "The cameras make it hard to do that."

So, before the starting gun, there will go another gold medal to Jamaica, and a likely 3-0 lead for the Caribbean island in the battle for sprint supremacy. With opponents like that, the final becomes little more than Bolt's race against his own record.

And the exuberant Jamaican didn't even have to boast about it. His running in Wednesday's semifinals did enough.

On a balmy evening, he ran hard on the curve and it was enough, happily closing it down just past the halfway mark and strolling past the line in 20.08 seconds _ still the fastest qualifying time.

If he had pushed, Bolt could easily have broken Tyson Gay's 2007 championship record of 19.76 seconds. Bolt's world record stands at 19.30.

Defending champion Gay is injured and out of the 200, and teammate Shawn Crawford had to push hard to qualify as third in Bolt's heat.

In the second semifinal heat, American sprinter Wallace Spearmon finished first in 20.14, edging Steve Mullings of Jamaica.

The temperature is set to exceed 30 C (85 F) at the Olympic Stadium on Thursday, and Bolt loves the heat. He cut through the swelter of Beijing last year on his way to three Olympic golds and as many world records.

It seems Bolt is the only one having questions whether he can break the record. He reminded everyone a foot injury had slowed his curve-running early in the season.

"I really have not done the same amount of work like I did for the 100," Bolt said.

Jamaican fans, though, have been working overtime all through the world championships, and they had a novelty to celebrate late Wednesday.

Brigitte Foster-Hylton followed up some Bolt-esque clowning ahead of the race with a clean run to claim the 100 hurdles title in a tight finish over Priscilla Lopes-Schliep of Canada.

And to rub in Jamaica's amazing speed, Delloreen Ennis-London took bronze.

The Americans were outrun yet again, with Olympic champion Dawn Harper fading to seventh place.

With titles in non-sprint events, the Americans top the medal table with three golds and eight medals overall, barely ahead Jamaica with three golds and seven total.

Thursday also has finals in the decathlon, 110 hurdles and the women's 400 hurdles and high jump.