Malcolm Ausbon, a California man, says short-fused singer Chris Brown and three members of his posse jumped him at a 24 Hour Fitness last year.
All, he says, because of a disputed foul during a pickup basketball game.
Ausbon is suing Brown, his goons and 24 Hour Fitness for unspecified damages claiming assault, battery, intentional infliction of emotional distress and negligence.
The lawsuit states that when Brown, 24, refused to acknowledge the foul called on him by Ausbon around 11 p.m., Ausbon "expressed his dissatisfaction."
Chris allegedly replied that he was a member of the Bloods street gang.
As Ausbon began to back away, members of the singer's entourage stepped in and said, "If you f--k with Chris, you f--k with us," the lawsuit states.