Is it good enough?
http://s1248.photobucket.com/albums/hh491/Cythe0/?action=view¤t=FacePunchtheresponse.gif

:)

I like what you've done. Arguably you haven't done much, but that's fine for a beginner. You have good easing and very good force. But I wouldn't have put that frame in with the bent arm just before he makes contact - it makes it look a bit unnatural. It's difficult to bend an arm that way. Aside from that, the thing you need to work on is stiffness. Try to find a way to make every joint move in every frame. The legs are completely static at the moment. It would be nice if they did something.

http://s1248.photobucket.com/albums/hh491/Cythe0/?action=view¤t=Easing.gif#!oZZ1QQcurrentZZhttp%3A%2F%2Fs1248.photobucket.com%2Falbums%2Fhh491%2FCythe0%2F%3Faction%3Dview%26current%3DPUNchintheface.gif
Here the legs move too.

By the way punching is the best move made in pivot.