Arizona Santa Clara Upset

How many times has a #15 seed beaten a #2 seed?
The only time I can remember is Steve Nash leading #15 Santa Clara to beat #2 Arizona.
Are there any other times?
And also, what other major upsets have their been in the NCAA March Madness?
4
1991-Richmond def. Syracuse
1993-Santa Clara def. Arizona
1997-Coppin State def. South Carolina
2001-Hampton def. Iowa State
God’s Mechanics: The Religious Life of Techies