Tosca was a State Junior Champion for Brockton High before coming to Holy Cross. He played four years for the Crusaders, and was the team's top player in three of those years. His career mark in individual matches was 55-8. He served as captain as a senior. He had success in regional tournaments as well, earing a spot in the quarterfinals of the Easterns, and as a co-medalist and semi-finalist in the Eastern Intercollegiates 1854.
After graduation, he won the 1959 State Amateur Title. In 1970 he became only one of eight players ever to win more than one Mass. Amateur Title. He also won five city open championships and eight city four ball titles.