In 2005 Andrei Arlovski and Tim Sylvia were two big fish standing in the very shallow pond that was the UFC heavyweight division. Arlovski was the reigning UFC heavyweight champion (the "interim" moniker recently being removed), running through overmatched opponents like a freight train. The only logical fight at the time was a rematch with former champion, Tim Sylvia.
In what looked like a replay of their first fight, Arlovski dropped Sylvia early in round one with a hard right hand. But the outcome would be different this day, as Big Tim was able to recover and land a short upper cut on the fragile chin of the champ, knocking him flat on his face. Sylvia finished off Arlovski with punches on the ground to regain the UFC heavyweight title.
It's only fitting that these two share a spot on my list as they have shared a lot throughout their careers. Both former UFC heavyweight champions, both former UFC interim heavyweight champions and both co-headlined Affliction PPVs only to be clobbered by Fedor. I smell a segue.