America's Aries Merritt takes gold in 110m hurdles as GB's Lawrence Clarke finishes fourth

August 8, 2012: Aries Merritt of the United States crosses the finish line ahead of Hansle Parchment of Jamaica to win gold in the Men's 110m Hurdles Final (GETTY IMAGES)

American Aries Merritt stormed to gold in the 110 metres hurdles at the London Olympics, holding off world champion Jason Richardson to cross the line in 12.92 seconds.

The 27-year-old made the most of perfect conditions on a balmy evening at the Olympic stadium to run his fifth sub-13 second time of the season.

Richardson won silver for the United States in 13.04 seconds and bronze went to Hansle Parchment who crossed the line in a Jamaican record time of 13.12.

Defending champion and world record holder Dayron Robles, who missed most of the season through injury, pulled up with what looked like a hamstring problem after the sixth hurdle.

China's former world record holder Liu Xiang, who won the title in Athens eight years ago, fell in his first-round heat after injuring his Achilles tendon.

Britain's Lawrence Clarke finished fourth.