In 1988 he became the first man to have won world titles at five officially recognized weights. In 1976 he was Olympic light-welterweight champion; he won his first professional title in 1979 when he beat Wilfred Benitez for the World Boxing Council (WBC) welterweight title. He later won titles at junior middleweight (World Boxing Association; WBA version) 1981, middleweight (WBC) 1987, light-heavyweight (WBC) 1988, and super-middleweight (WBC) 1988. In 1989 he drew with Thomas Hearns. He retired 1992.