Usain Bolt has won gold in the men's 200m to claim a historic Olympic sprint double in London.

The race was dominated by Jamaica, who took all three medals with world champion Yohan Blake closing Bolt down towards the line and Warren Weir clinching bronze.

There was no world record this evening, with Bolt stopping the clock at 19.32s - two-hundredths short of the Olympic record.

Bolt, who was constantly looking to his left to ensure that Blake wasn't catching too quickly, ran the bend strongly and managed to hold off the challenge of his young counterpart. Both men ran new season-best times.

Weir ran a new personal best to stave off America's Wallace Spearmon and Churandy Martina of the Netherlands, who finished fourth and fifth respectively.

Bolt, 29, becomes the first man in Olympic history to defend a 200m title.