This veteran Italian ace raced before the war with some success, but it was not until after the war that he achieved most of his success in the upper reaches of the sport. In 1938 he had been recruited into the Maserati team, ironically to counter the speed of the newly arrived rival Alfa Romeo 158s, one of which was now driven by his brother Emilio who was killed testing at Monza the following year. After the war he continued to race Maseratis, winning the Italian Championship in 1946 and 47 before joining his good friend Alberto Ascari at Ferrari in 1949, winning that season's Dutch Grand Prix. In 1954, Villoresi switched to Lancia together with Ascari but was deeply affected by Alberto's fatal accident at Monza in the spring of 1955. The following year he retired for good.