1991 San Marino Grand Prix

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.

The fourth pre-qualifier was Eric van de Poele in the Lambo, who edged out the second Dallara of Emanuele Pirro.

[1] 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.

[1] Ayrton Senna claimed his 55th pole position from Riccardo Patrese, Alain Prost, Nigel Mansell and Gerhard Berger.

At the lights, Patrese took the lead ahead of Senna, whilst Mansell, already slow off the line with gearbox problems, retired near the end of lap 1 after a collision with Martin Brundle.

In a strong lead, Patrese pitted for originally what appeared to be an early stop to slicks turned out to be more serious – a misfire with a faulty camshaft sensor.

Just after setting fastest lap, Berger was delayed in traffic, held up by the trio of Maurício Gugelmin, Julian Bailey and Thierry Boutsen.