Usain Bolt began his bid to add a second Olympic 200m crown to his two 100m titles with a hugely comfortable heat victory on Tuesday.
The Jamaican, who clocked an Olympic record 9.63 seconds to retain his 100m crown on Sunday, cruised to victory in 20.39secs.
Bolt has said he needs to win 200m gold again before he achieves his aim of becoming a "legend".
"It was an easy run, I'm enjoying it, it's my favourite event," Bolt said.
"It's getting pretty chilly. They say the weather should be good on Thursday [for the final] so we'll see."
Asked what he did to celebrate his 100m success, he said: "Nothing. I just chilled, met some friends and sat and talked."
Bolt's countryman and training partner Yohan Blake also breezed through, slowing down well before the line to clock 20.38s.
Blake had to settle for silver in the 100m, but is out to deny Bolt a second gold, having beaten him over 200m at the Jamaican trials
France's Christophe Lemaitre went quicker than both Jamaicans in winning his heat in 20.34 and Bolt nodded in approval as he watched his rival's run on a TV screen.