Balls of iron

I have just rewatched Ali vs. Lyle fight, and it has just popped into my head that this man (i.e. Clay/Ali) had the biggest balls in boxing history. He fought monsters as Liston, Foreman, Lyle, Frazier, Shavers, Wepner, etc. and even if he admitted he was terrified inside (as e.g. before 1st battle with Liston) he proceeded to be fearless on the canvas. Granted, there are some black holes in his carreer as e.g. his very controversial win over Pietrzykowski, a very probable fix in the 2nd Liston battle or specially loosened ropes in his Foreman battle, but they are nothing compared to what this man achieved. And I am saying this from the position of only a very mediocre fan who sometimes happened to keep my fingers crossed for Ali's opponents. I was very sad though when I saw him sick on Parkinson, it was almost hearetbreaking.