On this day in... 1985

Lotus ace Ayrton Senna had taken pole position, his second in a row, having converted his qualifying advantage into a maiden win in Portugal two weeks earlier, and looked set to make it back-to-back wins after leading for 56 laps of the 60-lap event.

But it was in the final three tours of a race that had originally been scheduled to run to 70 laps – only for the regulation two-hour limit to come into play – that chaos ensued among the pacesetters. 

The thirsty turbocharged engines of this mid-’80s breed of cars coughed and spluttered as they gulped down their final few litres of fuel and it was leader Senna who ran dry first. Into the lead for the first time, from 15^th on the grid, went Stefan Johansson, but the Swede’s Ferrari also slowed after just one lap at the front.

Next to pick up the pieces was Frenchman Alain Prost, whose McLaren had won in Brazil but failed to finish in Portugal. 

Prost defied the odds and held on to take his 18^th career win, the Porsche-built TAG engine in his McLaren seemingly blending the perfect mix of speed and efficiency, not unlike its driver, dubbed ‘Le Professeur’ for his pace and tactical nous. 

But that wasn’t the end of the controversy. The new World Championship leader’s car was a scant 2kg under the 540kg minimum weight limit, which led to his disqualification.

With the order reshuffled, runner-up Elio de Angelis in the second Lotus-Renault inherited his second career win, and with it the lead of the Drivers’ Championship, from the Arrows-BMW of Thierry Boutsen. Until Damon Hill finished second in Hungary 12 years later, Boutsen’s result would remain the British Arrows team’s best result in F1.

The bottom step of the podium was filled by Patrick Tambay, ahead of Prost’s team-mate Niki Lauda, Williams’ Nigel Mansell and Johansson, who’d completed enough laps to be classified as the final points scorer. 

De Angelis was as surprised as anyone to be declared the winner, for what would be the final time in his tragic and all-too-short F1 career, as he nursed the brakeless Lotus home.

San Marino Grand Prix, 1985

1. Elio de Angelis (ITA) – Lotus 97T-Renault, 60 laps

2. Thierry Boutsen (B) – Arrows A8-BMW, 59 laps

3. Patrick Tambay (F) – Renault RE60, 59 laps

4. Niki Lauda (AUT) – McLaren MP4/2B-TAG, 59 laps

5. Nigel Mansell (GB) – Williams FW10-Honda, 58 laps

6. Stefan Johansson (S) – Ferrari 156/85, 57 laps

Photographs courtesy of LAT Images