Thursday, August 21, 2008 - 11:58 PM

LaShawn Merritt has upset defending Olympic champion Jeremy Wariner to win gold in the men's 400 metres final at the Bird's Nest.

Merritt ran a personal-best time of 43.75 to take the victory ahead of Wariner (44.74) and another American, David Neville (44.80).

The two favourites for the race, Merritt and Wariner emerged even at the top of the final straight, but the Athens champion could not match his younger rival's pace in the final 50 metres.

Wariner, who went into the final having won 43 of his last 49 races, edged out Merritt at the World Championships in Osaka last year, but Merritt reversed the result at the US trials in Oregon earlier this year.

Merritt then lost twice to Wariner last month in Europe, setting the stage for their most meaningful meeting yet.

US men have dominated the Olympic men's 400m, winning the past six gold medals in the event and 11 of the past 13.