Greetings. *The duel is alot more simple than it looks.
First become familiar with the set up on the controller. *Then you should have no trouble finding the proper buttons to press at the right time. *All you have to do is press the correct button when it appears in the white part (between the two blue lines) in the scrolling bar. *Remember to use the normal directional buttons (not the analog stick) to improve your chances of beating the duel.
All it requires is good timing and patience. *Don't pay attention to what is going on with your character, just follow the pattern of button clicks. *If you can play Parapa the rappa you can do this duel.
(ps. edit out the caps by pressing on the little icon above your message titled "edit". *All caps are a major no no here. *See forum rules for more information on that)
Oh yeah and welcome to the forums, try introducing yourself in the Front Door minus the Capslock :)