I agree with a pasta dinner the night before- very little if any meat. On a side note, start drinking lots of water several days before the event (waiting until the night before or the day of won't do you much good). On the night before, don't work out. And when you go to bed just visualize yourself doing awesome- every movement is perfect, you defeat anyone you fight with no trouble at all, and you are standing on the podium with a gold medal around your neck!
good luck!!