Usain Bolt figures he’s a little more than 19 seconds away from cementing his Olympic legacy, and it’s going to take the race of a lifetime for anyone to stop him. In fact, he thinks conditions here are favorable for a world record.

American Wallace Spearmon knows he’s faster than Bolt. Unfortunately, Thursday’s track might not be the right venue.

“My car is faster,” Spearmon said this week, in what would amount to a pretty rare triumph over the fastest man to ever lace up a pair of shoes.

“He got a faster car,” Bolt conceded Wednesday, “but he worked on it. He’s done some stuff to it.”

Unless Olympic officials allow Spearmon to use that car on the track, he’s going to have his hands full with Bolt on Thursday at Olympic Stadium. There aren’t many other ways to beat the Jamaican sensation, who will try to become the first male sprinter to ever defend Olympic titles in both the 100- and 200-meter races. Since arriving in Britain nearly two weeks ago, Bolt has said repeatedly he feels winning both sprints here will certify him as a “legend.”

Spearmon was the third man to cross the finish line at the Beijing Games — he missed out on a bronze medal because he strayed from his lane — and isn’t ready to concede anything to Bolt, not behind the wheel and not on foot.

“They haven’t handed the medals out. Whoever crosses the line first, second and third, that’s who’s going to win the medals,” Spearmon said. “Right now, people just have opinions.”

Similar to Sunday’s 100-meter final, Bolt’s training partner Yohan Blake likely represents the biggest threat. At Jamaica’s track and field trials, Blake ran a 19.80, topping Bolt by three-hundredths of a second. While Bolt holds the world record (19.19), Blake is No. 2, having run a 19.26 last year in Brussels.

“I’m not really focusing on beating him,” said Blake, the silver medalist in Sunday’s 100. “I’m concentrating on running my race.”

Blake, 22, posted the fastest time in Wednesday’s semifinals, winning his heat in 20.01 seconds, barely edging Spearmon, who was just 0.01 seconds behind. Bolt had the fifth-best time (20.18) but never switched out of first gear.

“Today was all about just getting through,” he said. “I really pushed myself the first 70 meters, and then I tried to take it easy.”

Bolt can feel the young Blake breathing down his neck. His 100-meter victory wasn’t even one hour old Sunday, and Bolt made sure Blake could hear him tell reporters he wouldn’t surrender his crown easily.

Bolt considers the 200 his signature race, and it’s easy to see why. Even speedskaters must shake their heads at the way he flies around the curve in quite the same way. Bolt looked good in his early races and says he thinks a world record is possible Thursday.

“The track is fast. It’s going to be a good race,” he said.

If history is around the corner, Bolt certainly doesn’t seem nervous entering Thursday’s final. Prior to Wednesday’s semifinal race, Spearmon spotted him playing a game of tag with some children in Olympic Stadium about 10 minutes before lining up in the starting blocks.

“He is who he is,” Spearmon said. “He’s a big kid.”

Even if their rivalry is somewhat one-sided in recent years, the two sprinters are friendly. After Spearmon told Bolt about his Nissan GTR, Bolt went out and got one. It might not be faster, but Bolt still managed to upstage Spearmon.

“Now he has a sponsorship deal with them,” Spearmon said.

Barry Svrluga contributed to this report.