In 1991 Senna met with a jet skiing accident near Sao Paulo resulting in stitches to his head.
In the penultimate race of the 1990 season Senna and Prost again met with 5 points difference. Prost was driving for Ferrari and needed to win for championship. Senna who was already infuriated over preference given to Prost, collided at the first corner at 270 km/h spinning both out of the race and thus winning the championship.
It boiled down to the winner take championship between Senna and Prost at the Suzuka circuit in Japan in 1989. Frustrated Senna who found it difficult to pass Prost collided with him during a tight turn, prompting the later to retire. He went on to win the race, but disqualified for push start and collision. Prost won the championship.
Senna again came to Suzuka in 1991 with the winner take championship proposal but it was Nigel Mansell this time. Mansell spun off in the first corner and beached his car thus handling Senna an easy win.