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.
According to Ausbon, Brown and three members of his posse jumped him at the gym and began to "strike, punch, kick, pull and stomp" his head and body.
Ausbon ended up in the ER with a fractured rib and other injuries including cuts and bruises over his face and body, his lawyer Stephen Wegman said:
"He was jumped, beaten and dazed, and at some point my client made a police report about the incident and is waiting for police follow-up. Police never followed up."
"Imagine going to play a game of basketball, and you get jumped by four guys because you call a foul," he said. "This isn't for fame or fortune. He's got medical bills and issues."
Ausbon has suffered from post-traumatic stress disorder, distorted vision, dizziness, nervousness, embarrassment, fear and anxiety, the lawyer specified.
"All a result of some famous guy thinking he's above the law."
Wegman said he filed the civil lawsuit after a failed attempt to negotiate a private settlement with Brown's legal team, who "didn't want to communicate anymore."
"If Chris Brown isn't willing to compensate (Ausbon) for what he did to him, I'm not going to back down. It will be for a jury to decide."
Brown is also fighting an unrelated criminal charge that he punched a man in Washington, D.C., last October, and is in anger management rehab as a result.
He is still on probation after he pleaded guilty to beating pop singer Rihanna in 2009, agreeing to a no-jail, felony probation plea deal that's now in jeopardy.
He is due back in court February 28. For Chris Brown, or more accurately the people who cross Chris Brown, it appears the hits just keep on coming.