The USA had led from the start and appeared to be on course for gold but Yannick Agnel moved ahead of Ryan Lochte in the final 10m to claim the title in 3:09.83.
It meant Michael Phelps won his first medal of the London 2012 Games and his 17th overall, but it was France who were celebrating as they exorcised the memory of Beijing 2008, when they lost out on the touch to the USA.
Speaking after the victory team member Amaury Leveaux described the win as 'incredible'. 'It's a form of revenge for four years ago (when France came second to USA by 0.08 seconds). I was convinced of the victory. It's so good to win.'