After seven seasons in Brabham Nelson Piquet signed a contract with Canon Williams Team to drive their Williams/Honda car. Williams other driver, Nigel Mansell greeted his new teammate with some suspicion feeling that he deserved to be number one on the team, something that Williams was unwilling to do. Williams drivers stealing away too many points from each other and the 1986 title went to Alain Prost in his McLaren/TAG Porsche. Nelson Piquet scored four wins and finished third with 69 points in his first season in Williams team.

During 1987 Piquet had to fight Mansell hard, and even found enemies within his own team, Nelson suspecting they wanted a British champion, but with all his talent and courage he put everything behind him and won the title in great style. Scored 76 points Nelson Piquet became Three Times Formula One World Champion.