Answer
Joe Frazier lost his heavyweight title to George Foreman in 1973. The two men had fought before, in 1971, when Frazier won a unanimous decision. However, Foreman was a much bigger and stronger man than Frazier, and he was able to use his size and power to dominate the fight in 1973. Frazier was knocked down six times and was eventually stopped by the referee in the eighth round.