1991 Grand Prix of Portugal
22 September - Estoril: 308.850km (4.350km x 71 laps)


Pole Position: Riccardo Patrese, Williams-Renault FW14, 1:13.001


Results
 1. Riccardo Patrese       Williams-Renault FW14         1:35:42.304 (193.626 km/h)
 2. Ayrton Senna           McLaren-Honda MP4/6          -     20.941
 3. Jean Alesi             Ferrari 643                  -     53.554
 4. Pierluigi Martini      Minardi-Ferrari M191         -   1:03.498
 5. Nelson Piquet          Benetton-Ford B191           -   1:10.033
 6. Michael Schumacher     Benetton-Ford B191           -   1:16.582
 7. Mauricio Gugelmin      Leyton House-Ilmor CG911     -  1 lap
 8. Andrea de Cesaris      Jordan-Ford 191              -  1 lap
 9. Gianni Morbidelli      Minardi-Ferrari M191         -  1 lap
10. Roberto Moreno         Jordan-Ford 191              -  1 lap
11. Erik Comas             Ligier-Lamborghini JS35B     -  1 lap
12. Martin Brundle         Brabham-Yamaha BT60Y         -  2 laps
13. Satoru Nakajima        Tyrrell-Honda 020            -  3 laps
14. Mika Häkkinen          Lotus-Judd 102B              -  3 laps
15. Michele Alboreto       Footwork-Ford FA12           -  3 laps
16. Thierry Boutsen        Ligier-Lamborghini JS35B     -  3 laps
17. Ivan Capelli           Leyton House-Ilmor CG911     -  7 laps (Nose cone)
    
Fastest Lap: Nigel Mansell, 1:18.179 (200.310 km/h on lap 36)
Fastest lap time allowed to stand, despite Mansell was disqualified


Retirements    
    Stefano Modena         Tyrrell-Honda 020            - 15 laps (Engine)
    Nigel Mansell          Williams-Renault FW14        - 20 laps (Disqualified/Wheel changed outside pits/Accident)
    Aguri Suzuki           Lola-Ford L91                - 31 laps (Gearbox)
    Alain Prost            Ferrari 643                  - 32 laps (Engine)
    Gerhard Berger         McLaren-Honda MP4/6          - 34 laps (Engine)
    Emanuele Pirro         Dallara-Judd 191             - 53 laps (Engine)
    J.J. Lehto             Dallara-Judd 191             - 57 laps (Gearbox)
    Mark Blundell          Brabham-Yamaha BT60Y         - 59 laps (Suspension)
    Johnny Herbert         Lotus-Judd 102B              - 70 laps (Engine)
    
Did Not Qualify    
    Eric Bernard           Lola-Ford L91
    Gabriele Tarquini      AGS-Ford JH27
    Nicola Larini          Lamborghini 291
    Eric van de Poele      Lamborghini 291

Did Not Pre-qualify
    Fabrizio Barbazza      AGS-Ford JH27
    Olivier Grouillard     Fomet-Ford F1
    Alex Caffi             Footwork-Ford FA12
    Pedro Chaves           Coloni-Ford C4



    Race leaders:
    Riccardo Patrese        1-17 (17 laps =  73.950 km)
    Nigel Mansell          18-29 (12 laps =  52.200 km)
    Riccardo Patrese       30-71 (42 laps = 182.700 km)
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                                Starting Grid

 1. Riccardo Patrese       Williams-Renault FW14         1:13.001 (214.518 km/h)
 2. Gerhard Berger         McLaren-Honda MP4/6          -   0.220
 3. Ayrton Senna           McLaren-Honda MP4/6          -   0.443
 4. Nigel Mansell          Williams-Renault FW14        -   0.666
 5. Alain Prost            Ferrari 643                  -   1.351
 6. Jean Alesi             Ferrari 643                  -   1.851
 7. Mauricio Gugelmin      Leyton House-Ilmor CG911     -   2.265
 8. Pierluigi Martini      Minardi-Ferrari M191         -   2.393
 9. Ivan Capelli           Leyton House-Ilmor CG911     -   2.480
10. Michael Schumacher     Benetton-Ford B191           -   2.577
11. Nelson Piquet          Benetton-Ford B191           -   2.665
12. Stefano Modena         Tyrrell-Honda 020            -   2.706
13. Gianni Morbidelli      Minardi-Ferrari M191         -   2.748
14. Andrea de Cesaris      Jordan-Ford 191              -   2.935
15. Mark Blundell          Brabham-Yamaha BT60Y         -   3.037
16. Roberto Moreno         Jordan-Ford 191              -   3.079
17. Emanuele Pirro         Dallara-Judd 191             -   3.135
18. J.J. Lehto             Dallara-Judd 191             -   3.531
19. Martin Brundle         Brabham-Yamaha BT60Y         -   3.535
20. Thierry Boutsen        Ligier-Lamborghini JS35B     -   3.756
21. Satoru Nakajima        Tyrrell-Honda 020            -   3.925
22. Johnny Herbert         Lotus-Judd 102B              -   4.014
23. Erik Comas             Ligier-Lamborghini JS35B     -   4.225
24. Michele Alboreto       Footwork-Ford FA12           -   4.329
25. Aguri Suzuki           Lola-Ford L91                -   4.433
26. Mika Häkkinen          Lotus-Judd 102B              -   4.713
    
Did Not Qualify    
27. Eric Bernard           Lola-Ford L91                -   4.824
28. Gabriele Tarquini      AGS-Ford JH27                -   5.021
29. Nicola Larini          Lamborghini 291              -   5.138
30. Eric van de Poele      Lamborghini 291              -   5.265

Did Not Pre-qualify
31. Fabrizio Barbazza      AGS-Ford JH27                -   6.291
32. Olivier Grouillard     Fomet-Ford F1                -   6.499
33. Alex Caffi             Footwork-Ford FA12           -   6.520
34. Pedro Chaves           Coloni-Ford C4               -  10.857