Pablo Lugo was still a student when he was selected to represent Puerto Rico in the flyweight boxing tournament at the 1952 Helsinki Olympics. There, he lost his round one bout to Alfred Zima of Austria by decision. After the Games, Lugo joined the United States Army and served during the Korean War, eventually reaching the rank of Corporal during his time in the military. He also continued boxing and was selected to represent Puerto Rico in the flyweight tournament at the 1959 Central American and Caribbean Games, where he won a gold medal. Lugo retired shortly thereafter and never turned professional.