You have prepared a winning speech. You have rehearsed. You have worked with your mentor then rehearsed again and again.
You must want to win to win. Visualising yourself winning is a very important aspects of your preparation. When you close your eyes you should picture yourself having fun before the audience . You should notice the audience having fun as well, smiling and hanging onto every word.
Picture yourself winning and it will give you the attitude a winner. The audience will love it. The Judges will love it. You will love it.