Cassius Clay vs Henry Cooper 18.6.1963

The infamous fight between Henry Cooper and Cassius Clay from 1963. Cassius Clay would be knocked down for only the second time in his career and mystery still surrounds exactly how long did he get to recover in between rounds... More info below
Clay would enter with a record of 18-0, Henry Cooper 27-8-1. Henry Cooper had wanted to face current World Heavyweight Champion Sonny Liston, but his manager, fearing for his fighters safety against a monster like Liston, would not pursue it. Instead, they accepted the challenge of a young arrogant boxer named Cassius Clay. This was to be Clay's first fight as a pro outside of the United States and his last fight before beating Sonny Liston, becoming World Heavyweight Champion and changing his name to Muhammad Ali. Cassius Clay held little respect for Henry Cooper going into the fight. He claimed Henry a bum, and if he could not beat him in 5 rounds, he would not return to the USA for 30 days. Henry was only a warm up to the brash Cassius Clay. Henry Cooper's record although not great was respectable and he was the reigning Commonwealth and British Heavyweight Champion with 19 of his 27 wins coming by way of KO and most by way of his devastating left hook known as "Enry's ammer". Late in the forth round the young Cassius Clay was floored by the aforementioned punch and saved by the bell ending the round. Although Cassius was able to get to his feet, he was noticeably wobbled and the break between rounds was desperately needed. For Cooper however, it was too little too late. His face a crimson mask, cut wide open from Clay's repeated jabs with a torn glove, the referee had no choice but to end the fight in the following round when Clay turned up the heat. Clay's prediction of a 5th round KO had come to fruition but also a new level of respect for the veteran British boxer, 1 of only 3 men to ever drop Clay/Muhammad in his 61 fight career.
Interesting side note, 3 of the 4 knockdowns Muhammad Ali suffered during his career came by way of a left hook to the jaw... Sonny Banks, Henry Cooper and Joe Frazier. And 3 of those 4 fights in which Ali got knocked down, he went on to win... Chuck Wepner, Sonny Banks and Henry Cooper.