| «1991-13» | Portugal Grand Prix - XX Grande Premio de Portugal |
| 1991-09-22 | Estoril - Autódromo Fernanda Pires da Silva - 71 laps × 4.35 km : 308.85 km |
| Pos | Grid | Car | Driver | Constructor | Laps | Time / Gap | Interval | Points |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 6 | Riccardo Patrese | Williams • Renault | 71 | 1:35:42.304 | 193.626 km/h | 10 |
| 2 | 3 | 1 | Ayrton Senna | McLaren • Honda | 71 | +20.941 | +20.941 | 6 |
| 3 | 6 | 28 | Jean Alesi | Ferrari | 71 | +53.554 | +32.613 | 4 |
| 4 | 8 | 23 | Pierluigi Martini | Minardi • Ferrari | 71 | +01:03.498 | +09.944 | 3 |
| 5 | 11 | 20 | Nelson Piquet | Benetton • Ford Cosworth | 71 | +01:10.033 | +06.535 | 2 |
| 6 | 10 | 19 | Michael Schumacher | Benetton • Ford Cosworth | 71 | +01:16.582 | +06.549 | 1 |
| 7 | 7 | 15 | Mauricio Gugelmin | Leyton House • Ilmor | 70 | +1 lap | ||
| 8 | 14 | 33 | Andrea de Cesaris | Jordan • Ford Cosworth | 70 | +1 lap | ||
| 9 | 13 | 24 | Gianni Morbidelli | Minardi • Ferrari | 70 | +1 lap | ||
| 10 | 16 | 32 | Roberto Moreno | Jordan • Ford Cosworth | 70 | +1 lap | ||
| 11 | 23 | 26 | Erik Comas | Ligier • Lamborghini | 70 | +1 lap | ||
| 12 | 19 | 7 | Martin Brundle | Brabham • Yamaha | 69 | +2 laps | ||
| 13 | 21 | 3 | Satoru Nakajima | Tyrrell • Honda | 68 | +3 laps | ||
| 14 | 26 | 11 | Mika Hakkinen | Lotus • Judd | 68 | +3 laps | ||
| 15 | 24 | 9 | Michele Alboreto | Footwork • Ford Cosworth | 68 | +3 laps | ||
| 16 | 20 | 25 | Thierry Boutsen | Ligier • Lamborghini | 68 | +3 laps | ||
| 17 | 9 | 16 | Ivan Capelli | Leyton House • Ilmor | 64 | wing | ||
| 12 | 4 | Stefano Modena | Tyrrell • Honda | 56 | engine | |||
| DSQ | 4 | 5 | Nigel Mansell | Williams • Renault | 51 | wheel change outside pit | ||
| 25 | 30 | Aguri Suzuki | Lola • Ford Cosworth | 40 | transmission | |||
| 5 | 27 | Alain Prost | Ferrari | 39 | engine | |||
| 2 | 2 | Gerhard Berger | McLaren • Honda | 37 | engine | |||
| 17 | 21 | Emanuele Pirro | Dallara • Judd | 18 | engine | |||
| 18 | 22 | JJ Lehto | Dallara • Judd | 14 | gearbox | |||
| 15 | 8 | Mark Blundell | Brabham • Yamaha | 12 | suspension | |||
| 22 | 12 | Johnny Herbert | Lotus • Judd | 1 | engine | |||
| DNQ | 29 | Eric Bernard | Lola • Ford Cosworth | |||||
| DNQ | 17 | Gabriele Tarquini | AGS • Ford Cosworth | |||||
| DNQ | 34 | Nicola Larini | Lamborghini | |||||
| DNQ | 35 | Eric van de Poele | Lamborghini | |||||
| DNP | 18 | Fabrizio Barbazza | AGS • Ford Cosworth | |||||
| DNP | 14 | Olivier Grouillard | Fondmetal • Ford Cosworth | |||||
| DNP | 10 | Alex Caffi | Footwork • Ford Cosworth | |||||
| DNP | 31 | Pedro Chaves | Coloni • Ford Cosworth |
Fastest lap - 01:18.179 - 200.310 km/h - Nigel Mansell (lap 36)