^ but i'm sure he's at least been in a fight that lets him know that there is no "boxing" in a fist fight. or not usually...
anyways, what i like to do is wait for the big right from him, it will probably come and if he wants to "kick your ass" he'll deffinately lead with it... so keep your hands up, block it, and do a huge cross-over with your left hand right across his jaw. NEVER let up until hes on the ground not moving or he is unconcious, because when people start to lose they get desperate, and it leads to pain for you, even if you end up winning. hit him fast, and alot, always pay attention for a good time to hit, and once you see an opening, take it. whatever you do is dont try to push his hands down and punch him, but if the does that to you, move quick and hit him hard. take him to the ground if you can, put your shoulder into his hip and grab one leg or both behind the knee or at the side, put alot of pressure on him, lift him up and take him to the ground as hard as you can, but dont hurt yourself doing it. once he's on the ground pin his arms with your knees and hit him in the face till someone pulls you off, he goes unconcious, or stops struggling. thats usually a good rule of thumb to know that you won.
remember to keep your jaw down, hands up, and keep moving.