The 76-lap race does not start until 3.30 p.m. on Sunday so there is a lot of time to gaze anxiously at the sky and wonder if the rain is going to return, for the weather is anything but sunny. Though cloudy and overcast the rain holds off and all twenty cars that have qualified assemble on the 1×1 grid after the parade lap. As they shoot off towards the Ste. Devote comer Arnoux’s Renault is still spluttering on the back of the grid and Villeneuve has not made his usual electrifying getaway. As the mid-field runners crowd into the corner Daly seems to have total brain-fade and runs up the back of Giacomelli’s Alfa Romeo, which launches the Tyrrell into the air and it bounces off Jarier’s Tyrrell as it lands. While Pironi leads Jones, Reutemann, Laffite. Depailler and Piquet through Casino Square the shambles at the foot of the hill are being sorted out. Villeneuve has taken to the escape road, flicked the Ferrari round on the throttle and powered off up the hill. while Patrese has stopped, reversed out of the melee and promptly rammed the ATS. Daly (Tyrrell), Jarier (Tyrrell), Giacomelli (Alfa Romeo) and Prost (McLaren) are all out of the race and Lammers is soon in the pits having his front end repaired, while Pironi is in the lead with Jones hard on his heels. Reutemann in third place is acting as a nice buffer to keep Laffite. Although Pironi is leading from Jones the Ligier is not running away from the Williams, as it had done in Zolder two weeks before, Jones is really pressuring the Frenchman, with the nose of his car right under the Ligier’s gearbox, and it is a question of how long Pironi can withstand this sort of pressure. For a time they would pull away from the four cars following and then they would drop back and the first six would be nose-to-tail. The order is Pironi, Jones, Reutemann, Laffite, Depailler and Piquet, a hard bunch of chargers who are giving nothing away. The Ferraris are in trouble with their Michelin tyres and first Scheckter stops for a new set and then Villeneuve does the same, and while Scheckter eventually gives up the unequal struggle, considering the handling to be impossible, Villeneuve thrashes on and refuses to give in.
Before a third of the distance the leaders are beginning to lap such tail-enders as are left, and on lap 25 the differential breaks up in Jones’ transmission and the Williams is out of the race. This doesn’t mean that Pironi has it all his own way for Reutemann in the number two Williams begins to close up, with Laffite and Depailler hanging on tenaciously. Piquet is lonely fifth and a long way back come de Angelis, Mass, Andretti, Fittipaldi, Patrese, Arnoux and Villeneuve, while Jabouille is some laps behind after a pit stop to change tyres and Lammers is even further back after repairs. At half distance any pressure that Reutemann might have brought to bear on the Ligier has disappeared and Pironi looks set for his second Grand Prix victory. A lap down Villeneuve is battling away after his pit stop and Lammers has tucked in behind him with the ATS, doing a very spirited job of keeping up even though he is some laps behind. Pironi is in trouble as his gearbox is lumping out of third gear so he tries to use it as little as possible, and when he does have to use it he holds it in with one hand and does his steering with the other. The other Ligier is using up its brakes, or rather its driver is, and Depailler is pressing hard in fourth place. By lap 45 rain spots are falling near the Casino and though they develop into light rain and dampen the track surface they do not justify anyone stopping to change over to wet-weather tyres, but the surface becomes very slippery all round the course as the light rain spreads. Depailler’s fighting drive comes to an end when his Alfa Romeo engine blows up, which is a great relief to Laffite, and then on lap 55 as Pironi crosses Casino Square, being forced to use both hands on the steering wheel due to the slippery surface, his gearbox jumps out of gear and he slides out and hits the guard-rail, deflating the left front tyre and breaking the steering arm on that side. His race is over and Reutemann inherits the lead for Frank Williams, with no threats behind him, as Laffite is slowing and Piquet is too far back to cause trouble.
All Reutemann has to do is to pussy-foot home on the slippery surface to win with ease. At the back of the field Patrese has been battling with Arnoux until the rain has started when the Arrows driver has got all crossed up out of Casino Square and as he gathered it up Arnoux was going by and got clobbered by the Arrows. The Renault has been left by the road-side with a deflated left-front tyre and bent steering, while the Arrows have gone on its way. Mass has plodded with violent understeer on the downhill hairpins, wearing out his front tyres, but inherited fourth place as others have had worse trouble and Villeneuve’s never-say-die spirit has got him fifth place. while the prudent Fittipaldi has had a non-stop and careful run into sixth place.