#4. Revenge is Sweet (1991)
Score: #2 Duke 79, #1 UNLV 77
Is a #2 seed beating a #1 seed really an upset? If you consider that Duke lost by 30 in the championship game in 1990 and was expected to lose by the same type of margin in this game the following year, then yes. We can't even hate—Duke fan or not, this was epic.