This worked for me. I was in the thrid grade and having a lot of problems with some of the other students. I eventually got into a fist-fight. My defense at the principal's office was "My parents told me to fight back if someone hits me." That was the end of it, and being my first offense, I was free to go. The other kid got a three-day suspension -- he had problems before. I also never had a problem with the other students after that day. (This was in 1988.)
Good for you!