On the weekend between the Dutch and Italian GPs there was a World Sportscar Championship race at Spa. Stefan Bellof was sharing a Brun Porsche with Thierry Boutsen but collided with Jacky Ickx's Rothmans Porsche at Eau Rouge corner and was killed. Earlier Jonathan Palmer had crashed his Richard Lloyd Porsche heavily and broken his leg. Zakspeed did not bother going to Monza while Tyrrell decided not to replace Bellof immediately. Andrea de Cesaris had left Ligier and his place had been taken by Philippe Streiff while the new Haas Lola team appeared with a Hart-engined chassis being driven by Alan Jones.

Ayrton Senna took pole position in his Lotus-Renault with Keke Rosberg's Williams-Honda second fastest ahead of his team mate Nigel Mansell, Nelson Piquet (Brabham-BMW) was fourth with Alain Prost (McLaren-TAG) fifth and Elio de Angelis (Lotus-Renault) sixth. The top 10 was completed by Michele Alboreto (Ferrari), Patrick Tambay (Renault), Marc Surer (Brabham-BMW) and Stefan Johansson (Ferrari).

At the start Rosberg beat Senna into the first corner and Nigel Mansell quickly went ahead of the Lotus to make it a Williams-Honda 1-2. Senna had Prost right on his tail and Alain soon moved to third place. Mansell's car then hit electronic trouble and he pitted, rejoining almost exactly two laps behind. Prost was second with de Angelis up to third having overtaken the struggling Senna. It did not last long because Niki Lauda was soon moving up the order and he took third on lap 17. The order did not then change until Lauda broke a front wing and had to pit. He was followed in by Rosberg who needed new tyres. This left Prost ahead of Rosberg with Senna third, de Angelis fourth and Piquet fifth. Rosberg was soon back in the lead but on lap 45 Keke suffered an engine failure and so Prost was ahead again with Piquet having got the better of Senna to finish second. Senna was third with Lauda fourth and Johansson fifth ahead of de Angelis.