31. Bucknell vs. Kansas (2005)
The Bucknell Bison existed for 110 seasons before this game. Yet, this was their first victory in the NCAA tournament as well as a first for the Patriot League. The N0. 14 seed faced the Kansas Jayhawks in what should have been a total mismatch (via New York Times).

Many analysts consider the Jayhawks the best team in the league before the season. Things didn’t pan out that way but they were still a strong unit. However, they fell apart in the tournament as Bucknell produced a famous result. They won 64-63 on a famous day in Oklahoma City.