The 1985 Belgian Grand Prix was a Formula One motor race held at Spa-Francorchamps on 15 September 1985. It was the thirteenth round of the 1985 FIA Formula One World Championship. The race was the 43rd Belgian Grand Prix, the 31st to be held at Spa and the second since the circuit had been rebuilt and re-opened at half its original length in 1979. The race was held over 43 laps of the seven kilometre circuit for a total race distance of 301 kilometres. The race was won by Brazilian driver Ayrton Senna driving a Lotus 97T. It was Senna's second World Championship victory and the first of five he would win at Spa-Francorchamps. Senna won by 28 seconds over British driver Nigel Mansell driving a Williams FW10. Third was World Championship points leader, French driver Alain Prost driving a McLaren MP4/2B. The win promoted Senna to third in the drivers' standings and third place allowed Prost to expand his lead over Ferrari driver Michele Alboreto to 16 points. Originally scheduled to take place on 2 June 1985, the Grand Prix was rescheduled for September after the recently resurfaced track became damaged during the race weekend. Race summary Track surface and postponement This was the second Belgian Grand Prix to occur at a reconfigured Circuit de Spa-Francorchamps, with the first being the 1983 race. Race organisers opted to resurface the track with a material called Stress Absorbing Membrane Interlayer that intended to provide improved grip in wet-weather conditions at a cost of £3 million. Fédération Internationale du Sport Automobile (FISA), the governing body of Formula One, was queried about the resurfacing work and replied it would approve if race organisers complied with a regulation that mandates any such work occur 60 days beforehand. Local bureaucracy and a harsh winter caused delays to the work, which were reportedly finished ten days before the event's scheduled date of 31 May, and forced a cancellation of a pre-race test session at the circuit. Organisers did not refer the incident to the Fédération Internationale de l'Automobile and went ahead. Warm weather, the powerful turbocharged cars of the time, and their wide, slick tyres, damaged the track during the Friday practice session. Repairs to the circuit were conducted overnight and undamaged turns were also addressed. After around 25 minutes into the Saturday practice session, all on-track activity stopped, since drivers noticed the damage and held