LONDON, England - Usain BOLT won his third gold of the London 2012 Olympic Games at the Olympic Stadium on Saturday, anchoring Jamaica's 4x100m relay team to gold in a world record time of 36.84 seconds.

Handed the baton level with USA's fourth man Ryan Bailey, Bolt ran a brilliant final leg to win by two metres, stopping the clock at under 37 seconds for the first time in history.

Bailey brought USA home in 37.04, their second national record of the Games and equal to the world record set by Jamaica at the Daegu 2011 world championships 12 months ago. The USA team of Trell Kimmons, Justin Gatlin, Tyson Gay and Bailey could hardly have done more to wrestle the gold from Jamaica's grasp.

Indeed, they led until the last changeover, when Bolt produced his third scintillating performance in seven days to become the first man ever to win three gold medals at two Games.

Yohan Blake, who ran the third leg, also won his third medal after taking silver medals behind BOLT in the 100m and 200m, while Nesta Carter on first and Michael Frater on second have another Olympic relay gold to go with those they won doing the same jobs at Beijing 2008.

Trinidad and Tobago picked up their second medal in less than an hour, taking bronze in 38.12 after Canada, who had crossed the line third, were disqualified for running on the inside line at the final changeover.

The final was always going to be a battle between the big two sprint nations, and the tension was ramped up further in the semifinals when first Jamaica and then USA ran the quickest times ever seen in Britain. With former world champion Gay to come into the USA foursome, and Bolt to anchor for Jamaica, the final was set up to be something special.

And so it was. Kimmons got USA off to a great start in lane seven, with Nesta Carter chasing hard for Jamaica in six. Kimmons handed to Gatlin just ahead and the 100m silver medallist sped down the back straight pursued by Frater.

Blake took the baton just behind Gay, and made up the ground around the bend to set BOLT away shoulder-to-shoulder with Bailey. They set off together, running step-for-step for 40 metres until BOLT eased away, his giant strides eating up the track once again.

He crossed the line and threw his arms wide in celebration as the world record figures flashed out. Saluting the crowd, BOLT held up three fingers. Call it what you like - a three-peat, a double-triple - it was a fitting way for the athletics star of London 2012 to bring the track and field action of these Games to a close.