British horse Red Cadeaux was denied on the line by France's Dunaden in the closest finish in the 151-year history of the Melbourne Cup.
The Ed Dunlop-trained Red Cadeaux looked set to make a triumphant debut in the 'two-miler' as the horse, ridden by Michael Rodd, led the race inside the final furlong.
However, Christophe Lemaire, riding the French second-favourite Dunaden, kept pace and edged out Red Cadeaux in a photo finish to claim the AUS $6.2m (£4m) prize.
The winning margin was the shortest in 151 runnings of the race and Lemaire was reduced to tears after the judges' verdict was announced.
"It's incredible - it's a great moment for me," Lemaire told the Sydney Morning Herald.
"I didn't know if I could ride or not. It was for me already a pleasure to come to the Melbourne Cup as a spectator, so I was waiting for the judgement," he added.
"I had a fall just before the Arc [Prix de l'Arc de Triomphe] weekend and I lost eight winners, four group ones, so I know what it is to be in your armchair and watching your horses win."