Ali vs. Foreman — Rumble in the Jungle (1974)

Ali invented the rope-a-dope in Kinshasa, absorbing 300-plus punches from the unbeaten Foreman over seven rounds before knocking out the champion who had a 40-0 record with 37 KOs. This upset vaults above Ali vs. Frazier III in tactical brilliance, shifting boxing from brawling to psychology. The fight drew 60,000 live fans and an estimated 1 billion television viewers worldwide, making it the most-watched single sporting event of its era. Ali's 8th-round knockout remains the defining moment of his career.