Batman AC Titan fight

I am in museum fighting the titan.
I got on his back once, taking out all other enemies, keep on doing stun attack, but he does not seem to be very impressed by that. Somehow i cant hit very fast, i do stun attack, hit him a few times with normal speed, then he hits me if i dont run away.
Somehow i thought the stunning is more effective. How to beat that guy?
Answer #1
Do you mean soluman grundy? or the giant one with the other inmates competing for penguin?
Answer #2
I mean the one that almost hits me when falling down after the penguin shot at that thing hanging above me. The guy with the other inmates.
Answer #3
Check dis out:
http://www.youtube.com/results?search_query=walkthrough+batman+arkham+city+soluman+grundy&oq=walkthrough+batman+arkham+city+soluman+grundy&aq=f&aqi=&aql=&gs_sm=e&gs_upl=4503l19253l0l19432l40l34l1l2l0l9l708l6364l3.11.6.3.2.1.1l27l0
Answer #4
He’ll go down after a few times you get on his head.
Answer #5
Beat him, thank you