Willie McGinest has been sued for beating the hell out of a man at an L.A. restaurant back in December ... with the alleged victim claiming the attack all went down because of a comment that was made about USC.
The lawsuit, obtained by TMZ Sports, was filed by Blake Adams in L.A. county earlier this month.
In the docs, Adams claims he was dining at Delilah in West Hollywood on Dec. 9 -- when he noticed McGinest, a famous USC alum, walking past his table.
Adams says in the suit he asked the Trojans legend about SC's most recent game -- a loss in the Pac-12 Championship to Utah -- when McGinest bristled.