To easily win a tournament, select Yamcha as your fighter. As soon as the battle begins, use the Wolf's Fang Fist (making sure the opponent does not block the four punches; if so do not use the move and just block until a chance is given). The seventh hit will knock your opponent into the air and the final attack should hit the opponent out of the ring. If the opponent does not go out, knock him back near the edge then use the Wolf's Fang Fist (once again making sure that they do not block the four punches).