1991 Grand Prix of San Marino
28 April - Imola: 307.440km (5.040km x 61 laps)


Pole Position: Ayrton Senna, McLaren-Honda MP4/6, 1:21.877


Results
 1. Ayrton Senna           McLaren-Honda MP4/6           1:35:14.750 (193.671 km/h)
 2. Gerhard Berger         McLaren-Honda MP4/6          -      1.675
 3. J.J. Lehto             Dallara-Judd 191             -  1 lap
 4. Pierluigi Martini      Minardi-Ferrari M191         -  2 laps
 5. Mika Häkkinen          Lotus-Judd 102B              -  3 laps
 6. Julian Bailey          Lotus-Judd 102B              -  3 laps
 7. Thierry Boutsen        Ligier-Lamborghini JS35      -  3 laps
 8. Mark Blundell          Brabham-Yamaha BT60Y         -  3 laps
 9. Eric van de Poele      Lamborghini 291              -  4 laps (Fuel pump)
10. Erik Comas             Ligier-Lamborghini JS35      -  4 laps
11. Martin Brundle         Brabham-Yamaha BT60Y         -  4 laps
12. Mauricio Gugelmin      Leyton House-Ilmor CG911     -  6 laps (Engine)
13. Roberto Moreno         Benetton-Ford B191           -  7 laps (Gearbox/Engine)
    
Fastest lap: Gerhard Berger, 1:26.531 (209.682 km/h on lap 55)
    

Retirements    
    Stefano Modena         Tyrrell-Honda 020            - 20 laps (Transmission)
    Andrea de Cesaris      Jordan-Ford 191              - 24 laps (Gearbox)
    Bertrand Gachot        Jordan-Ford 191              - 24 laps (Spun/Suspension)
    Ivan Capelli           Leyton House-Ilmor CG911     - 37 laps (Puncture/Spun)
    Eric Bernard           Lola-Ford L91                - 44 laps (Camshaft sensor)
    Riccardo Patrese       Williams-Renault FW14        - 44 laps (Electrics/Engine)
    Satoru Nakajima        Tyrrell-Honda 020            - 46 laps (Transmission)
    Gianni Morbidelli      Minardi-Ferrari M191         - 51 laps (Gearbox)
    Aguri Suzuki           Lola-Ford L91                - 59 laps (Spun)
    Jean Alesi             Ferrari 642                  - 59 laps (Spun)
    Nelson Piquet          Benetton-Ford B191           - 60 laps (Spun)
    Nigel Mansell          Williams-Renault FW14        - 61 laps (Gearbox/Accident)
    
Did Not Start    
    Alain Prost            Ferrari 642                   Spun on warm-up lap
    
Did Not Qualify    
    Gabriele Tarquini      AGS-Ford JH25
    Fabrizio Barbazza      AGS-Ford JH25
    Alex Caffi             Footwork-Porsche FA12
    Michele Alboreto       Footwork-Porsche A11C
    
Did Not Pre-qualify    
    Emanuele Pirro         Dallara-Judd 191
    Olivier Grouillard     Fomet-Ford F1
    Nicola Larini          Lamborghini 291
    Pedro Chaves           Coloni-Ford C4


    Race leaders:
    Riccardo Patrese        1- 9  (9 laps =  45.360 km)
    Ayrton Senna           10-61 (52 laps = 262.080 km)
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                                Starting Grid

 1. Ayrton Senna           McLaren-Honda MP4/6           1:21.877 (221.601 km/h)
 2. Riccardo Patrese       Williams-Renault FW14        -   0.080
 3. Alain Prost            Ferrari 642                  -   0.318
 4. Nigel Mansell          Williams-Renault FW14        -   0.489
 5. Gerhard Berger         McLaren-Honda MP4/6          -   0.690
 6. Stefano Modena         Tyrrell-Honda 020            -   1.634
 7. Jean Alesi             Ferrari 642                  -   2.068
 8. Gianni Morbidelli      Minardi-Ferrari M191         -   2.885
 9. Pierluigi Martini      Minardi-Ferrari M191         -   2.930
10. Satoru Nakajima        Tyrrell-Honda 020            -   3.468
11. Andrea de Cesaris      Jordan-Ford 191              -   3.614
12. Bertrand Gachot        Jordan-Ford 191              -   3.654
13. Roberto Moreno         Benetton-Ford B191           -   3.778
14. Nelson Piquet          Benetton-Ford B191           -   3.932
15. Mauricio Gugelmin      Leyton House-Ilmor CG911     -   3.964
16. J.J. Lehto             Dallara-Judd 191             -   4.097
17. Eric Bernard           Lola-Ford L91                -   4.106
18. Martin Brundle         Brabham-Yamaha BT60Y         -   4.178
19. Erik Comas             Ligier-Lamborghini JS35      -   4.330
20. Aguri Suzuki           Lola-Ford L91                -   4.479
21. Eric van de Poele      Lamborghini 291              -   4.673
22. Ivan Capelli           Leyton House-Ilmor CG911     -   4.725
23. Mark Blundell          Brabham-Yamaha BT60Y         -   4.901
24. Thierry Boutsen        Ligier-Lamborghini JS35      -   5.121
25. Mika Häkkinen          Lotus-Judd 102B              -   5.447
26. Julian Bailey          Lotus-Judd 102B              -   6.099

Did Not Qualify
27. Gabriele Tarquini      AGS-Ford JH25                -   6.298
28. Fabrizio Barbazza      AGS-Ford JH25                -   7.788
29. Alex Caffi             Footwork-Porsche FA12        -   8.403
30. Michele Alboreto       Footwork-Porsche A11C        -   8.885

Did Not Pre-qualify
31. Emanuele Pirro         Dallara-Judd 191             -   4.428
32. Olivier Grouillard     Fomet-Ford F1                -   4.912
33. Nicola Larini          Lamborghini 291              -   5.009
34. Pedro Chaves           Coloni-Ford C4               -   9.362