Three-time World Superbike champion Jonathan Rea retired from the race after appearing to clip the bike of Eugene Laverty after the Aprilia rider came off his bike with 20 laps to go.
Laverty narrowly avoids horror collision at Magny-Cours
The win marks Davies 27th World Superbikes win, and sees him solidify his third-place position in the overall standings.
Rea wins third straight title after spectacular ride
The 30-year-old is just nine points behind Tom Sykes, who finished down seventh, in second with two rounds of racing left.
'Thank goodness he wasn't hit!' - Van der Mark spins off in middle of track
Savadori flips off bike in nasty Magny-Cours crash