i hate fighting and i dont usually do it but a sure fire way to win (saved my ass probably 10 or so times) fake a left to his chest and when he goes to block punch as hard as you possibly can in the side of the jaw and he will go down for sure, i usually put a bic lighter in my hand but ive seen footage of a valve breaking in the lighter from the blow and exploding in the guys hand. then when there down if it is a seriosu matter boot him in the ribs once or twice