By Symone Goss, World-Track
The Jamaican who at the weekend set a world record of 9.58secs to win the 100m, raced off the corner and hit the front at the top of the stretch to win comfortably.
"I am ok. I may have looked tired this morning because the 200m were earlier than the 100m," Bolt said.
"Why I wear a T-shirt now? I just wanted to try something new. I am a little bit tired, but ok.
"I need to get a little rest this evening and then I will be fresher tomorrow."
Frances David Alerte (20.51) ran home for second place, beating countryman Martial Mbandiock (20.55).
The second heat went to American former Olympic champion Shawn Crawford, who powered home to 20.37secs.
Steve Mullings, a strong candidate to win a medal in this event also looked good when running 20.23 to win the third quarter-final heat.
Mullings, who will definitely be a key member on the Jamaican 4x100m relay team was the fastest qualifier of the second round.
Completing the heat winners was Panama’s Alonso Edward, who ran 20.33 to beat American reigning bronze medallist Wallace Spearmon, at 20.44.
Defending champion Tyson Gay withdrew from the event with a groin injury