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50 years ago yesterday at the Convention Centre in Miami, Cassius Clay defeated Sonny Liston to become the champion of the world.

We were joined by boxing writer and historian Thomas Hauser, author of Muhammad Ali: His Life and Times, to discuss the legacy from that fight.

"It was enormously important for two reasons. Number one is simply an athletic competition. It marked the emergence of Cassius Clay who would become Muhammad Ali and a great fighter. Also if Cassius Clay hadn't beaten Sonny Liston and not been the heavyweight champion of the world, everything he did afterward would have had far less impact. If he was a beaten fighter who'd been knocked out by Sonny Liston, not many people would have cared had he changed his name. Not many people would have cared that he refused induction into the United States Army. He wouldn't have become the towering social, political and religious figure he became."  

Clay beat Liston, who at the time was considered to be the greatest, by technical knockout in the seventh round and Hauser cited the boxing icon's speed, footwork and hands as the key factor.

Hauser also told us about the interesting public perception of Clay as an entertainer rather than a serious fighter before the bout and also touched on why he changed his name to Ali just weeks later.

But this fight would be the beginning of the end for Liston. While the infamous ghost punch fight was still to come, the first defeat to Clay "exposed him as vulnerable" for the first time according to Hauser.