Throughout the 1930s and 1940s Argentine cyclist Mario Mathieu amassed an impressive list of results with wins across South America. Mathieu won his first national road race title in 1935 before winning back-to-back titles in 1937 and 1938, followed by a fourth title in 1942. During this time he also won the Latin American road race championship in 1940 and 1941. Mathieu’s best record came at the Clásica del Oeste-Doble Bragado stage race, which he won on six occasions (1935–36, 1938–40, 1942). He was also a strong track cyclist, winning the Six Days of Buenos Aires in 1943 and 1945, in addition to finishing second in 1944 and 1946. In 1948 Mathieu represented Argentina at the London Olympics and came seventh in the team road race.