The 71-lap race was won by Alain Prost, driving a McLaren-Honda, with Ivan Capelli second in a March-Judd and Thierry Boutsen third in a Benetton-Ford.

Both drivers complained of little grip on the rarely used Estoril circuit, which was compounded by slow turns which exposed the Straight-4 Megatron engine's lack of throttle response.

The second start was aborted after Derek Warwick stalled his Arrows A10 and was hit by de Cesaris, with Luis Pérez-Sala (Minardi) and Satoru Nakajima (Lotus).

[citation needed] Prost's lead built up to 7 seconds and would last until the flag, while Senna was being troubled by an erratic (and ultimately false) fuel readout which was telling him he was using too much.

It was the first time all season other than when Prost suffered from severe misfires at both the British and Italian GP's that a McLaren-Honda had been passed on track by any other car.

He had accidentally set off his fire extinguisher, with the resultant freezing of his leg with carbon dioxide causing his foot to slip off the pedals.

Maurício Gugelmin, Nelson Piquet (Lotus-Honda), Michele Alboreto (Ferrari), Riccardo Patrese (Williams-Judd) and Thierry Boutsen (Benetton-Ford) were hotly contesting the last point place in 6th.

On lap 57, Senna, still having problems with his fuel readout, pitted for a tyre change and was passed by Alboreto, Boutsen and Derek Warwick, falling to 6th.