Try and move your head into the fist at the same time as he throws the punch. The resultant effect of the rapid transferrence of the combined velocity into that of your face will produce a numbing effect in the region of the locality to which the velocity was directed, which will also possibly be transferred to the more general contents of your cranium. Alternatively, dodge, duck, dip, dive, and dodge. I dunno, you'd wanna stop the punch. If you don't mind being in the fight, avoid being hit, lessen the blows, and take advantage of any opening in his guard. If you want the fight to be over quickly, follow my initial post, run the shit away, or talk him out of it.