Punch him a few times, he's a push over. Then fight the guys who come in to help. Unfortunately, he throws every size at you. You have a one armed guy and a Titan in this battle along with little guys and the Joker. Try to clean up the little guys as best you can while staying on the move. I highly recommend using the Electric Charge on the Hammer guy. When it's just the two big guys and the Joker, go for the Titan. Hit him with the Super Stun and then attack him until you ride him. Use him to attack the one armed guy. Rinse and repeat until the Titan is dead, then take the one armed guy down and finally the Joker. Be sure to watch out for train cars coming randomly throughout the fight. They can do some decent damage.