
39. Wisconsin vs. Kentucky (2015)
Yes, we know, it probably seems crazy that a top-seeded team beating another No. 1 seed is an upset. But this truly was one of the biggest of the season. The Kentucky Wildcats had a phenomenal roster with the likes of Karl-Anthony Towns and Devin Booker (via The Guardian).

On paper, they were one of the greatest teams in modern history. Or they should have been, at the least. After cruising to a 38-0 unbeaten record, they met the Badgers in the Final Four. Then, Wisconsin did what nobody else was able to achieve by beating Kentucky.