LONDON — In his first appearance at the London Olympics, Usain Bolt did what he had to do to advance to the 100-meter semifinals, overcoming a slow start to win his heat in 10.09 seconds Saturday.

Bolt dominated the Beijing Games four years ago, winning golds in world-record times in the 100, 200 and 4x100 relay — something no man had ever done at an Olympics. At the 2009 world championships, he lowered his 100 mark to 9.58, which still stands.

But he’s been less-than-outstanding more recently. A false start knocked him out of the dash at last year’s world championships, and he lost to training partner Yohan Blake in the 100 and 200 at the Olympic trials.