On November 30, 1979 Antuofermo defended his title against Marvelous Marvin Hagler in Las Vegas, Nevada, the fight resulting in a controversial 15-round draw. Judge Duane Ford scored the bout in Hagler's favor, 145–141. Judge Dalby Shirley scored it for Antuofermo, 144–142. Judge Hal Miller had it even at 143–143. The draw enabled Antuofermo to retain his title. In his next defense, against Alan Minter, also in Las Vegas, he lost the title by a 15-round split decision. The bout featured a wild disparity in scoring with a Venezuelan judge scoring the fight for Antuofermo while a British judge had Minter winning 13 of the 15 rounds. They had a rematch in London on June 28, 1980. Minter retained the crown by a TKO (on cuts) in eight rounds.