25 February 1964
On This Day This man "Shook The World" when Cassius Clay soon to be Muhammad Ali defeated Sonny Liston to become Heavyweight Champion of the World, changing boxing forever.
The fight nearly didn’t go ahead as Muhammad Ali worked himself up into such a frenzy at the weigh in taunting Liston that during his medical, his heart rate was 120 beats per minute, more than twice its normal rate, and his blood pressure was 200/100. Dr. Alexander Robbins, the chief physician of the Miami Boxing Commission, said that he was "emotionally unbalanced, scared to death, and liable to crack up before he enters the ring." If Ali's blood pressure didn't return to normal, the fight would be canceled. Many others also took Clay's antics to mean that he was scared.
A second examination conducted an hour later revealed Ali's blood pressure and pulse had returned to normal. The rises was caused by exertion of the act rather than fear and Ali later said, "Liston's not afraid of me, but he's afraid of a nut."