Though Senna's consistency, the car's competitiveness, and the Williams's unreliability at the beginning of the season gave him an early advantage, Senna insisted that Honda step up their engine development program and demanded further improvements to the car before it was too late. These modifications enabled him to make a late-season push, and he won three more races to secure the championship, which was settled in Japan when Mansell (who needed to win), went off at the first corner while running third and beached his Williams in the gravel trap. Senna finished second, handing the victory to teammate Gerhard Berger at the last corner as a thank-you gesture for his support over the season. Senna was planning to move to the Williams team for the 1992 season, but Honda's CEO, Nobuhiko Kawamoto, personally requested that he remain at McLaren-Honda, which Senna did out of a sense of loyalty; in addition to Alain Prost's recommendation Honda had played an important part of bringing Senna with them to McLaren.