At first, the 1987 championship was a four-way battle between Williams drivers Nelson Piquet and Nigel Mansell, Lotus driver Ayrton Senna, and McLaren driver and defending two-time champion Alain Prost. Eventually, it became a straight fight between Piquet and Mansell, who between them finished with nine wins from the season's sixteen races. Mansell took six wins to Piquet's three; however, he only recorded three other points finishes while Piquet recorded nine (including seven second places). The duel was settled in Piquet's favour at the penultimate race of the season in Japan, when Mansell crashed heavily in practice and injured his back, ending his season and handing Piquet his third Drivers' Championship.