I cut my knuckle on his teeth. But then again, his face basically exploded. xD
Oh, just remembered another one. Same year in school, and the exact opposite happened. The guy just looked stunned I'd hit him and got over it. Shows the first one was a total fluke.

My friend has been knocked out for a few seconds in one punch. I wasn't there to see it but apparently it was pretty hilarious. He looked at a chav. Chavs do not like him. Chances are he said something to the guy, though.

The face is a really stupid place to punch someone. The skull is a much harder bone than your fist. The chest has plenty of weakspots to get at, and you're much better off using your elbow to crack someone across the face with anyway. Hurts you less and them more.