Trainer Alain de Royer Dupre secured his sixth French Derby victory as Reliable Man left it late to seal an impressive win in Chantilly.
Ridden by veteran Gerald Mosse, Reliable Man edged out Bubble Chic, while favourite Baraan finished third.
Mosse guided the grey through the field from the inside before chasing down and then bypassing Bubble Chic through the centre in impressive style.
British horse Colombian narrowly lost out for third in a photo finish.
"It's a special pleasure to have won this for the sixth time," said De Royer Dupre, who last won it with Darsi in 2006.
"I was always quietly confident with this horse. He may not have had the race records of others in the race but he is a horse I have always had high hopes for.
"The ground too didn't give me too much concern as it has always got a little bit of give in the ground.
"I knew I was going to win 400 metres out. I dedicate this victory to the trainer as he has always shown confidence in me."
The much-fancied Baraan, ridden by Christophe Lemaire, was almost 20 lengths adrift after the first two furlongs and looked set for a particularly poor result.
But he finished strongly, only to be outdone by the imperious Reliable Man.
Reliable Man retains his unbeaten record in winning the Group One race but Bubble Chic, meanwhile, is forced to settle for second place for the sixth successive time in the Prix du Jockey Club.