Rapper Claims The Game Sucker Punched Him

2Eleven tells us, he had no idea Game even wanted to fight him -- but last Thursday at Weezy's 30th birthday celebration at a Hollywood nightclub, 2Eleven says Game sucker punched him out of nowhere in the back of the head. TMZ posted video footage of the aftermath.

2Eleven says it came as a total shock -- because he had been sitting at the same table with Game, Birdman and others for a full hour with no problems.

As we reported, Game's telling the opposite story -- saying 2Eleven was talking smack, and that's what started it -- but 2Eleven insists he was just minding his own business.