Determined to avenge his defeat to Joe Frazier, Ali builds a rustic training camp in Deer Park, PA, and goes on to defeat a parade of contenders before losing to Ken Norton in 1973. The loss jeopardizes a Frazier rematch, but a recommitted Ali beats Norton in a second bout, setting up an encore with Frazier, who was dethroned by George Foreman earlier that year. This time, Ali beats his nemesis, with his reward being the 1974 "Rumble in the Jungle" with Foreman in Zaire. Against all odds, Ali KOs an exhausted Foreman to regain the heavyweight title, and becomes an idol around the world. Another epic victory over Frazier, 1975's "Thrilla in Manilla," follows, but the toll of so many brutal fights starts to show. After several up-and-down bouts (and retirements), Ali vows to return to the ring, and in December 1981 he loses badly to Trevor Berbick. Finally, Ali retires for good and The Greatest travels the world as a goodwill ambassador.