Elbert Foster was just a few days into his job as a long-term substitute when he got into a fight with a 14-year-old student in his math class.
One witness says the fight started after Foster ordered a disruptive student leave his classroom, but the student refused.
Foster claims he was defending himself. He told reporters he was hit three times in the side of his face, his shoulder was separated and a tooth went through his lip.
Foster could face criminal charges.