McLaren joined the Cooper factory F1 team alongside Jack Brabham in 1959 and won the 1959 United States Grand Prix at age 22 years 104 days, becoming the youngest ever GP winner (not including the Indianapolis 500) up to that time. He followed that with a win in the Argentine Grand Prix, the first race of the 1960 Formula One season, and he would finish runner-up that season to Brabham.