Compiled a professional boxing record of 65 wins (31 KOs), 10 losses, and two draws. In 77 fights, Giambra was never knocked out as a professional. He retired in 1963 following a split decision loss to Joe DeNucci.
A professional boxer, Giambra fought Denny Moyer for the vacant WBA (World Boxing Association) super welterweight title on October 20, 1962. He lost a unanimous decision.