Kickboxer 4: The Agressor (1994)

Continuity mistake: At the final fighting scene (David Sloan vs.Tong Po), you can see that Tong Po's hair (a half shaved head with only a ponytail on it) is as fake as it can be: everytime when he moves his head a bit to rough around (sweeping his ponytail around while fighting) clearly shows that he's wearing a special kind of wig attached to his head. That 'wig' is so badly attached that it looks like he's got rimples on the back and on top of his head.

Darcy: He said you're a hard man. Just how hard are you, Mr. Jones?
David Sloan: Um... hard enough.