Carlos Lucas took up boxing in 1947 and, four years later, became the Chilean national middle-heavyweight champion, in addition to finishing second at the Latin American Championships. He was not considered a medal contender when he was selected to represent his country at the 1956 Melbourne Olympics, but he won a surprise bronze medal as a light-heavyweight by surviving to the semi-finals, losing only to upcoming silver medalist Gheorghe Negrea of Romania. He won another bronze medal at the 1959 Pan American Games, but then dropped down to the middleweight division for the 1960 Rome Olympics. There, he was eliminated in round two by upcoming bronze medalist Yevgeny Feofanov of the Soviet Union. He retired from active competition shortly thereafter and never turned professional.