On January 22, 1973, in Kingston, Jamaica, the 24-year-old George Foreman pulls off a stunning upset, defeating reigning champion Joe Frazier in four minutes and 35 seconds to win the heavyweight championship of the world.

At 6’3″ and 217 1/2 pounds, four inches taller and 3 1/2 pounds heavier than Frazier, “Big George” was the 1968 Olympic gold medalist and had won his last 37 fights, 34 of them by knockout. The boxing world, however, sniffed that he hadn’t truly faced anyone like “Smokin’ Joe,” and Frazier–the 1964 Olympic winner and unbeaten heavyweight world champion since 1968, including a 1971 victory over the great Muhammad Ali–was put at a 3-1 favorite before the match in Jamaica.

Billed as the “Sundown Showdown,” the bout was supposed to be one more triumphant step for Frazier on his way to a multimillion-dollar rematch with Ali. It was Foreman, however, who roared out in front from the beginning. Using his greater size to advantage, Foreman slammed Frazier with uppercuts, knocking him down six times in two rounds, as the crowd went wild in Kingston’s National Stadium. Foreman’s last punch, a perfect right uppercut, lifted Frazier’s stocky body into the air for an instant before he hit the canvas yet again. Frazier struggled to his feet, but at that point, 1:35 into the second round, the referee Arthur Mercante called an end to the bout, declaring Foreman the winner on a technical knock-out (TKO).

The Frazier-Foreman fight in January 1973 was the first boxing match broadcast on the Home Box Office (HBO) cable television network. The celebrated announcer Howard Cosell called the match for TV, making one of sports history’s most memorable calls when he repeated “Down goes Frazier! Down goes Frazier!” It was Foreman, and not Frazier, who would take on Ali in that multimillion-dollar championship bout, held the following summer in Zaire (now the Congo) and dubbed the “Rumble in the Jungle.” Ali won the match late in the eighth round, regaining the world heavyweight crown and handing Foreman the first loss of his professional career.