For such a fight, you must train hard to just develop the self confidence to enter such a match. You must, by way of your self confidence, know that you can win. When Ving Tsun (Wing Chun) practitioners go to fight and are defeated then the mentality is not to think that the other person is better than himself. Instead he needs to ask himself what were his mistakes to invite the attack. This is the kind of positive thinking which any fighter must possess.