Paul Williams always had ****py defense and loved to throw punches, his iron chin finally gave out that night, it was bound to happen. Marquez on the other hand knocked Pacquiao out after failing to do so in 3 fights. Much higher skill set in this match than Williams vs Martinez
The Williams KTFO was more shocking because of where they were at in their respective careers. Pacquiao (and Marquez too) had shown signs of slipping in the third fight. Whereas Williams was ascending prime fighter who had just recently beat Martinez. When Williams got KTFO it was just incredible to think about.
Now if Pacquiao had been KTFO in the second fight at his prime it would have been unthinkable and one of the GOAT wins ever.
I was concerned Pacquiao had actually died. Then I was concerned Pacquiao would be in a Gerald McClellan state. Alas, he never returned to the ring the same fighter. He was finished after that fight.