There have been plenty! Here's a few.

Mayorga losing to anyone,
Duran losing to anyone.
Tarver losing to Dawson twice.
Tarver losing to California State Athletic Commission.
Ali losing to Frazier was special!!!!!
Rahman being crushed by Lewis.
Johansson being crushed by Patterson.
Rademacher being crushed by Patterson.
Broner losing to Maidana.
Judah losing to anyone.
Ortiz losing to Mayweather. (Head butts come from punks.)
Berto losing to Ortiz.

That's enough, I don't want anyone to think I'm sadist.