Olympics champion Usain Bolt began his bid to add a second Olympic 200 metres crown to his two 100m titles with a hugely comfortable heat victory.
The Jamaican, who clocked an Olympic record 9.63 seconds to retain his 100m crown on Sunday, cruised to victory in 20.39secs which also includes Nigeria's Noah Akwu.
Bolt has said he needs to win 200m gold again before he achieves his aim of becoming a 'legend'.
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.
Ecuador's Alex Quinonez was in fact the fastest qualifier in a national record of 20.28.
Meanwhile, World number one Aries Merritt qualified impressively in the 110m hurdles in 13.07 as China's Liu Xiang crashed out injured at the first hurdle.
Also, Olympic champion and world record holder Barbora Spotakova topped qualifying in the javelin, the Czech throwing the spear out to 66.19m with her first throw.
Ethiopia's Tirunesh Dibaba, the defending champion, qualified fastest for the final of the 5,000m in 14:58.48. Dibaba retained her Olympic 10,000m crown on Friday.