McLaren's domination of the season continued at the 79-lap French Grand Prix as Niki Lauda gave the team its fourth win in five races.
The home crowd were anticipating more French success as Patrick Tambay in a Renault took pole with Alain Prost back in fifth, four places ahead of team-mate Lauda. And it was Tambay who got the best start and within a few laps it was a local 1-2 as Prost led the chasing group.
But Prost ran wide on a corner and damaged his wheels which necessitated a pit stop. By the time he resumed he had lost almost a lap and a later stop to sort a brake issue meant he finished out of the points.
Tambay led until halfway when he misjudged his braking point allowing Lauda through, and although the Frenchman chased hard for the remainder of the race he was never able to put enough pressure on Lauda's McLaren.
Defending champion Nelson Piquet suffered his fourth retirement in five races when a fire in the engine of his Brabham forced him out.
Nigel Mansell, who raced despite his mother's death three days earlier, drove well to take third but was highly critical of the marshals. "On one lap I came over the brow of the hill before the pits flat out in fifth to find one of them crossing the track about 50 feet in front of me. You could say I was unimpressed. In fact it shook me rigid."
Mansell also survived an incident when battling with Derek Warwick when the pair came up fast behind the much slower Arrows of Marc Surer. Mansell braked heavily forcing Warwick to swerve but he locked his brakes and slid into Surer. The suspension on the Renault broke, trapping Warwick in the car for several minutes. He escaped with bad bruising.