On lap 11 Piquet spun into the sand and was forced to retire. On lap 14 the weather started to come into contention as rain began on parts of the circuit, benefitting Senna, who is particularly skilled in wet conditions. Ivan Capelli seized his historic chance on the following lap as he overtook Prost to take the lead, the first time a nonturbo car had led a Grand Prix for over 4 years. His lead only lasted for a few hundred metres, as the extra power of the Honda engine allowed Prost to regain the lead going into the next corner. Capelli made several further attempts to overtake Prost, who was struggling with a faulty gearbox, before retireing with an electrical failure, to the dismay of the Italian.
By then Senna was catching Prost rapidly, and with traffic, a malfunctioning car and a tricky wet/dry surface, conditions were favourable to the Brazilian. On lap 27, as they attempted to lap Andrea de Cesaris, Satoru Nakajima and Mauricio Gugelmin, Senna managed to force his way through as Prost was delayed by the Italian's Rial. Senna then put in a succession of fastl laps, breaking the former lap record and building a lead of over 3 seconds, despite being delayed while lapping Nakajima, which allowed Prost to catch back up.
With slick tyres on a track that was now wet, Senna was gesturing for the race to be stopped but this was not the case. The race ran out its entire course and Senna led home from Prost; Honda was delighted with a 1-2 in their homeland. Boutsen took another 3rd place, whilst Berger recovered his 4th place after Alboreto held up Nannini who had to settle for 5th, and Patrese collected 6th. Nakajima was 7th.
With the victory on this race, Senna clinched the World Championship. His 8th win of the season beat the record held by Jim Clark and Prost.