SUZUKA, Japan (AP) -- Alain Prost and Ayrton Senna crashed at the Japanese Grand Prix for the second time in two years, allowing Senna to walk away with this year's world Formula One championship if no protest is filed.
Last year, the two archrivals crashed in one of the final laps, giving Prost the world championship. This year, the two collided again -- but just seconds after the start.
The two drivers, locked in a close battle for this year's title, started at the front of the pack, with Senna on the pole.
France's Prost, driving a Ferrari, moved quickly in front, forcing Senna to try to regain the lead by passing from the inside.
But as Prost maneuvered his car to the right for the first turn of the course, he collided with the Brazilian, sending parts of Senna's red and white McLaren-Honda flying into the air. Both drivers spun out into the dirt and later walked off the track.
"Prost opened the door," Senna said after retiring from the race. "But there was only room for one" car.
The race continued, and it was not immediately clear whether Prost and Ferrari would file a protest.
Senna's points lead now is big enough that Prost couldn't win the championship even if he wins the season's final race at Adelaide, Australia on Nov. 4.
1. Nelson Piquet, Brazil, Benetton- Ford, 1 hour, 34 minutes, 36.824 seconds, average 123.077 mph. 2. Roberto Moreno, Brazil, Benetton- Ford, 1:34:44.047. 3. Aguri Suzuki, Japan, Larrousse- Lamborghini, 1:34:59.293. 4. Riccardo Patrese, Italy, Williams- Renault, 1:35:13.082. 5. Thierry Boutsen, Belgium, Williams- Renault, 1:35:23.708. 6. Satoru Nakajima, Japan, Tyrrell- Ford, 1:35:49.174. 7. Nicola Larini, Italy, Ligier-Ford, 1:34:58.244, one lap behind winner. 8. Pier-Luigi Martini, Italy, Minardi- Ford, 1:35:01.090, one behind. 9. Alex Caffi, Italy, Arrows-Ford, 1:35:12.139, one. 10. Philippe Alliot, France, Ligier-Ford, 1:35:48.434, one.
11. Derek Warwick, Britain, Lotus-Lamborghini, 38 laps completed. 12. Johnny Herbert, Britain, Lotus-Lamborghini, 31. 13. Michele Alboreto, Italy, Arrows- Ford, 28. 14. Nigel Mansell, Britain, Ferrari, 26. 15. Emanuele Pirro, Italy, Dallara- Ford, 24. 16. Eric Bernard, France, Larrousse- Lamborghini, 24. 17. Gianni Morbidelli, Italy, Minardi- Ford, 18. 18. Ivan Capelli, Italy, Leyton-Judd, 16. 19. Andrea De Cesaris, Italy, Dallara- Ford, 13. 20. Mauricio Gugelmin, Brazil, Leyton- Judd, 5. 21. David Brabham, Australia, Brabham-Judd, 2. 22. Gerhard Berger, Austria, McLaren- Honda, 1.