marvelous marvin hagler (born marvin nathaniel hagler; may 23, 1954 – march 13, 2021) was an american professional boxer and film actor who competed in boxing from 1973 to 1987. he reigned as undisputed middleweight champion from 1980 to 1987. he was the world middleweight champion from 1980 to 1987. hagler fought out of brockton, massachusetts. he won the championship from alan minter, in london, and successfully defended it eleven times before losing in a controversial fight with sugar ray leonard. hagler retired after that fight to live and work in italy.