BEIJING (AP) — Usain Bolt played to the cameras before his 200-meter semifinal, slowed down in the middle and still rallied to beat rivals who were running much harder. Then he promised to go all out in the final.

If he does — and he hasn't really yet in these Olympics — there doesn't seem to be any way he can be beaten.

Bolt won his semifinal in 20.09 seconds Tuesday night, keeping alive his chances for the first 100-200 Olympic double since Carl Lewis in 1984.

The Jamaican sprinter, who set the world record in the 100 at 9.69 seconds Saturday, beat defending 200 champion Shawn Crawford of the United States by 0.03 second. The noticeable difference, though, was that Bolt appeared to be loping to the line, while Crawford was busting across at full speed.

"I wouldn't say jogging," Bolt said. "I'm just trying to get through to the next round. I didn't know if he was running. I just wanted to make sure I was in good position."

American Wallace Spearmon used a late burst to finish third and will join a third American, Walter Dix, in the final Wednesday night.

Bolt had fun during his short stay on the track, pretending to smooth his closely shaven hair before the start and pointing toward the camera before he climbed into the starting block.

Starting in Lane 6, it took him about 10 steps to make up the lag against Spearmon in Lane 7. Crawford was in Lane 5 and actually looked like he might win the heat, but Bolt passed him for the win — and possibly to send a message to one of his prime contenders for the gold.

The big question, however, is are there any real challengers?

Bolt's win by 0.2 second in the 100 was impressive not just because of the world record, but because he was hamming it up — slapping his chest and holding out his hands — with about 20 meters to go. His left shoelace was even untied.

He broke his own world record by 0.03 second. Next up is a run at Michael Johnson's mark of 19.32 in the 200, a record set 12 years ago.

"I don't know," Bolt said when asked what the final would be like. "I'm just going to run my heart out and hope for the best."

In the 400-meter semifinals, American rivals Jeremy Wariner and LaShawn Merritt won their respective semifinals. Wariner, the defending Olympic champion, is 14-3 lifetime against Merritt, but Merritt has two of those wins in the last year, including at the U.S. Olympic trials.

In other qualifying heats, world record-holder Dayron Robles of Cuba and American David Oliver advanced easily in the 110-meter hurdles. Chinese star and defending Olympic champion Liu Xiang withdrew from the event before the first round with an injured foot.

There were no surprises in the second round of women's 200 heats. Americans Allyson Felix, Muna Lee and Marshevet Hooker all made it through, as did the Jamaican trio of Veronica Campbell-Brown, Sherone Simpson and Kerron Stewart.

In the 100, the Jamaicans swept and the Americans finished 4-5-8. The two countries could again earn six of the eight spots in Thursday night's 200 final.

"It fueled my fire," Lee said of Jamaica's dominance. "I'll just think about that in the final."

In women's 5,000-meter semis, American Shalane Flanagan kept alive her hopes for two Olympic medals. That would be a first for an American in the short history of women's distance running at the Olympics.

Flanagan overcame stomach troubles to win bronze in the 10,000 and said she's still celebrating that success.

"It's beautiful," she said. "It's kind of like I'd imagine if you have a newborn child. You're fascinated with it. You're like, 'Wow, that really is mine? That's mine?"'