clear of the rest of the field when, on lap 11, de Angelis attempted to overtake the Brabham at Surtees Corner, only to make contact and send both cars spinning. Piquet duly went through into the lead, while Patrese rejoined the track ahead of Prost but was soon caught and passed by the Renault. De Angelis also rejoined, but continued for only two laps before retiring with an engine failure. At quarter distance, Piquet led Prost by around 10 seconds, with Patrese a further 10 seconds back and holding up Cheever, René Arnoux, Mansell and Patrick Tambay. On lap 20 Arnoux spun at Surtees, dropping him to the back of the field. There were no further changes among the front-runners until the pit stops, during which both Brabhams hit trouble: Patrese was delayed by a misfitted rear wheel, while Piquet was held up by a malfunctioning wheel-nut gun. Piquet nonetheless retained his lead over Prost, while an unscheduled second stop for Cheever (due to a loose helmet visor which was taped by his pit crew) left Tambay in third and Mansell fourth, with Andrea de Cesaris up to fifth in the Alfa Romeo and Derek Warwick sixth in the Toleman. In the closing stages, Tambay suffered brake problems, allowing Mansell past on lap 66 before spinning off at Druids two laps later. This moved the second Toleman of Bruno Giacomelli into the top six, while also ending Tambay's challenge for the Drivers' Championship. Shortly afterwards, Warwick had a bizarre accident when his cockpit fire extinguisher leaked, giving him burns to his right hand and leg, though he held on to fifth place. Up front, Piquet cruised to his second consecutive win, finishing 6.5 seconds ahead of Prost with Mansell a further 24 seconds back. De Cesaris finished four seconds behind Mansell and ten ahead of Warwick, who in turn finished eight seconds ahead of teammate Giacomelli. Patrese ultimately finished seventh, while Arnoux was ninth and Cheever tenth, both one lap down on Piquet. With one race to go, Prost still led the Drivers' Championship but by only two points over Piquet, while Arnoux's failure to score left him needing to win in South Africa to have any chance of the title. The race also saw the last appearance of the Theodore team, which was struggling financially and had scaled back to one car for Roberto Guerrero. Guerrero finished 12th, one