Williams took a step up for the season, keeping their driver line-up of Patrese and Mansell. Mansell dominated the first round in South Africa, qualifying in pole position and winning the race by 24 seconds from his teammate, Patrese. Nigel Mansell won the next four rounds for Williams, at Mexico City, Interlagos, Catalunya and Imola, Patrese coming second in all but one (the Spanish Grand Prix at Catalunya, where he retired after spinning off). Mansell's five victories in the opening five races was a new record in Formula One. Senna won the next race in Monaco, ahead of both Williams cars, which finished second and third. In the next race, in Canada, both Williams cars retired: Mansell spun off on entering the final corner (he claimed that Senna pushed him off) and Patrese had a gearbox failure. Mansell went on to record four more Grand Prix wins, including at the British Grand Prix. (In the final round, in Adelaide, the two Williams cars again retired, Mansell after Senna violently crashed into the back of him, and Patrese with electrical problems.) Williams won the Constructors' Championship with 164 points, 65 points more than second-place McLaren. Mansell became World Champion, scoring 108 points, with Patrese finishing second with 56 points. Placing first in nine races, Mansell had set a new record for the most wins by a single driver in one year.