LONDON (Reuters) - Usain Bolt began his bid to complete an unprecedented Olympic sprint double-double when the Jamaican breezed through his opening 200 meters heat with the minimum of fuss on Tuesday.

Less than 48 hours after retaining his 100 crown on Sunday, Bolt eased into Wednesday's semi-finals of his favorite event by winning the opening heat in a pedestrian 20.39 seconds.

Bolt is hot favorite to follow up his Beijing 200 gold and wants to cement his place as a "legend" in the sport.

The 200 final is on Thursday.

(Reporting by Justin Palmer, editing by Mark Meadows)