Can Blake burst Bolt's double bubble?

Even when he slows to a jog, Usain Bolt is as fast as he needs to be.

His sidekick, Yohan Blake, is looking like the closest thing there is to a true challenger.

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Is there anyone in the Olympic 200-metre final on Thursday night who can outsprint both of the Jamaicans to win the gold?

"Yeah, man. That's why we are racing," said Wallace Spearmon of the United States.

"If they weren't beatable, they would just hand them medals, and we'd race for third."

Actually, it's not outlandish to suggest the bronze is the only medal that's seemingly not destined for Bolt or Blake in the 200.

"There's a lot of people there who have come to spoil the party," Bolt said, "so we'll see."

He's trying to become the first man with two Olympic titles in the 200, part of his oft-stated goal of becoming a "living legend" in London.

As it is, Bolt already successfully defended his 100 title from the Beijing Olympics by winning that final on Sunday in 9.63 seconds -- the second-fastest time in history -- to join Carl Lewis of the US as the only men with consecutive golds in the dash.

Four years ago, he went 3 for 3, winning the 100, 200 and 4x100 relay, all in world-record time. He went on to break his marks in the two individual races at the 2009 world championships -- records that still stand, 9.58 in the 100 and 19.19 in the 200.

Asked about the chances of a world record on Thursday, Bolt replied: "There's a possibility, definitely. I can't say (for sure), but the track is fast. It's going to be a good race."

The other medals at stake on Thursday are in the decathlon, with world record-holder Ashton Eaton of the US taking a 220-point lead over teammate Trey Hardee into the last five events; the men's triple jump, where Americans Christian Taylor and Will Claye are among the favorites; the men's 800 meters; and the women's javelin.

In addition to Bolt, Blake and Spearmon, the 200 field includes Christophe Lemaitre of France, Churandy Martina of the Netherlands, Warren Weir of Jamaica, Alex Quinonez of Ecuador, Anaso Jobodwana of South Africa.

At the Beijing Games, Martina and Spearmon finished second and third to Bolt in the 200 but didn't head home with medals because they were disqualified for running out of their lanes.

Blake nearly made a big blunder in Wednesday's semi-finals, easing up so much that he nearly let the hard-charging Spearmon and Lemaitre catch him at the finish line. But Blake -- given the nickname "The Beast" by his pal Bolt because of the intensity of his practices -- got across first in 20.01 seconds, 0.01 ahead of Spearmon and 0.02 ahead of Lemaitre.

"You know the nature of 'The Beast'," Blake said.

"I find myself out in front, and I just cruised from there."