The 1991 San Marino Grand Prix was a Formula One motor race held at Imola on 28 April 1991. The 61-lap race was the third race of the 1991 Formula One season and was won from pole position by Ayrton Senna, driving a McLaren-Honda, with team-mate Gerhard Berger second and JJ Lehto third in a Dallara-Judd. Pre-race With the team under new management having been sold by Cyril De Rouvre, Stefan Johansson was replaced at AGS by Formula One debutant Fabrizio Barbazza. Qualifying Pre-qualifying report In the pre-qualifying session on Friday morning, Andrea de Cesaris was fastest in the Jordan, just under four tenths of a second faster than JJ Lehto's Dallara in second. De Cesaris' team-mate Bertrand Gachot was third, just a few hundredths behind Lehto. The fourth pre-qualifier was Eric van de Poele in the Lambo, who edged out the second Dallara of Emanuele Pirro. It was van de Poele's first progression through to the main qualifying sessions, and the first time in 1991 that a Dallara had failed to pre-qualify. Apart from Pirro, those who failed to pre-qualify included Olivier Grouillard in the new British-built Fomet-1 chassis debuted by the Fondmetal team. Despite teething troubles which prevented him from progressing any further, Grouillard said he was happy with the new car. Seventh was the other Lambo of Nicola Larini, and bottom of the time sheets was Pedro Chaves in the sole Coloni, who suffered a gearbox failure during the session. Pre-qualifying classification Qualifying report Ayrton Senna claimed his 55th pole position from Riccardo Patrese, Alain Prost, Nigel Mansell and Gerhard Berger. Qualifying classification Race Race report The formation lap saw two dramatic incidents: Prost spun off the track at Rivazza Turn, followed by Berger, who was able to continue. However Prost stalled the engine and did not take the start. At the lights, Patrese took the lead ahead of Senna, whilst Mansell, already slow off the line with gearbox problems, retired at the end of lap 1 after a collision with Martin Brundle. He was followed out by Nelson Piquet who spun off on lap 2, Aguri Suzuki who spun off on lap 3 behind the leaders and Jean Alesi who also spun off on lap 3 attempting a rather foolhardy pass on Stefano Modena. In a strong lead, Patrese pitted for originally what appeared to be an early stop to slicks turned out to be more