10 Powerless Characters Who Have Defeated Superman
4. Harley Quinn - Harley's Little Black Book #5
Thirty years after the iconic boxing match between Harley Quinn and Muhammad Ali, the writers of Harley's Little Black Book decided to relive the experience the glorious 1978 comic gave us, by having Harley also trounce the Man of Steel.
The scenario is basically entirely the same as the one between Ali and Kent, as the pair box against one another in a ring that takes away Supes' powers. However, it is equally as unfair, as we learn beforehand that Quinn has been practicing boxing since she was a kid, whereas Superman generally doesn't have time given the whole 'usually found saving the world' thing.
After reenacting the knockout that Muhammad Ali managed, Harley and Superman manage to escape the clutches of their alien captor - though not before our red and blue hero realises why Quinn is such a threat to other heroes like Batman.