LaMotta refused to become a pawn of the mob and for years was prevented from getting the matches that could lead to a title. He finally won the middleweight championship from Frenchman Marcel Cerdan on June 16, 1949, with a technical knockout. Cerdan, who had beaten the legendary Tony Zale to win the title, was killed in an airplane crash while flying back to the United States for a rematch. LaMotta later admitted to the Kefauver Committee, a panel investigating corruption in boxing, that he had thrown a 1947 fight with Billy Fox to get that title shot. Earlier in 1947, LaMotta had been offered $100,000 to throw a different fight, an offer he refused. He accepted only that part of the deal for throwing the Fox fight that guaranteed him a chance to win the title and refused the money that went with it.
In beating Tiberio Mitri, LaMotta retained his title, and again successfully defended it in a fight against Laurent Dauthuille which ended with a knockout in the fifteenth round. The judges who scored the fight round by round had given it to Dauthuille, and if the fight were played by today's rules, which limit a fight to twelve rounds, LaMotta would have lost. And he did lose his next defense of his title to Robinson the following year. In the famous "St. Valentine's Day Massacre" of 1951, he lost the crown to Robinson. LaMotta, who himself had brutalized so many opponents, was being beaten so badly that the referee stopped the match in the thirteenth round.