Which was the bigger upset?

[JAB5239]

Really is not even close? At the time nobody was giving Ali much of a chance... And, Liston was looked as an unbeatable beast...

I think it has to be taken into consideration what both fighters did before and after their respective wins. Looking at it that way it is easily Douglas over Tyson in my opinion.

[Suckmedry]

Buster over Tyson, definitely