BEIJING — Usain Bolt confirmed his greatness in style, starting in Lane 5 and ending in a one-for-the-ages celebration before a worldwide audience.

Bolt, the youngest finalist in the men's 200-meter final, obliterated the competition on Wednesday night at National Stadium. He seized his second gold of the Olympics, winning in 19.30 seconds, a world record. Michael Johnson held the previous mark of 19.32 seconds, which was set at the 1996 Atlanta Games.

"I was feeling really tired," Bolt said later, moments before his 22nd birthday. "This track is really quick. I left everything on the track this evening."