The 1986 Italian Grand Prix was a Formula One motor race held at Monza on 7 September 1986. It was the thirteenth race of the 1986 Formula One World Championship. The 51-lap race was won by Brazilian driver Nelson Piquet, driving a Williams-Honda. Piquet's British teammate and Drivers' Championship rival, Nigel Mansell, finished second, with Swede Stefan Johansson third in a Ferrari. The other two championship challengers, Frenchman Alain Prost and Brazilian Ayrton Senna, both failed to finish, Senna suffering a transmission failure in his Lotus-Renault at the very start of the race and Prost being disqualified halfway through for illegally switching to his spare McLaren-TAG after the start of the formation lap. The win moved Piquet into second place in the Drivers' Championship, five points behind Mansell and three ahead of Prost, with three races remaining. Qualifying report During the second qualifying session at Monza, the Benetton-BMW of Gerhard Berger was recorded as being the fastest car along the start-finish straight, with a top speed of . He was followed by four more BMW-powered cars: teammate Teo Fabi, the Brabhams of Derek Warwick and Riccardo Patrese, and the Arrows of Thierry Boutsen. The fastest non-BMW powered car was the Williams-Honda of Nigel Mansell, with a top speed slower than that of Berger. Despite this, Berger could only qualify fourth, while Fabi took his second consecutive pole position. Alain Prost lined up alongside Fabi on the front row, despite being nearly half a second slower in his McLaren-TAG and recording a top speed over slower than Berger's. Drivers' Championship leader Mansell was third, ahead of Berger, while Brazilian pair Ayrton Senna (Lotus-Renault) and Nelson Piquet (Williams-Honda) made up the third row. The top 10 was completed by Warwick, Keke Rosberg in the second McLaren, Michele Alboreto in the Ferrari and Patrese; Alboreto's position was notable as he had missed the first day of qualifying after injuring his arm in a motorcycle crash. The race saw the debut of local driver Alex Caffi, deputising for Allen Berg at Osella, as well as the debut of the French AGS team, whose Motori Moderni-powered JH21C was driven by another local driver, Ivan Capelli. With the number of entries increased to 27 at both this race and the next race in Portugal, FISA decided to allow all the cars to start. Caffi was the beneficiary of this decision, starting 27th behind Capelli and Osella