The “Beast” has lived up to his nickname, a woman claims.

NFL star receiver Brandon Marshall — whose list of run-ins with the law is as long as a football field — allegedly slugged the woman at a Chelsea nightclub, The Post has learned.

Marshall was at Marquee early Sunday when he got into an argument with a group of friends celebrating a birthday, law-enforcement sources said.

At around 4 a.m., birthday girl Christin Myles, 24, left an upper floor of the posh hot spot to greet a friend downstairs.

When she tried to get back upstairs, a bouncer told her she had to wait because there was a fight between two football players — Marshall, 27, and an unknown athlete — who were being thrown out, the sources said.

She later met up with her friends, who by then were arguing with Marshall and the other football player outside, sources said.

Marshall — who earned his nickname with his aggressive style of play — then allegedly cold-cocked Myles in the left eye. She suffered a black eye. It wasn’t clear if he allegedly intended to strike her or one of her pals.

Myles filed a police report Monday with the 10th Precinct against Marshall, sources said. She told cops she waited a day before making the allegation because she was nervous about Marshall’s high-profile status.

Marshall’s lawyer denied that the first fight involved his client or his friends.

“While attempting to leave to avoid the melee, [Marshall’s wife] was struck in the face by a thrown bottle. She suffered serious injury,” the lawyer, Harvey Steinberg, said. “The mayhem continued outside.

“Finally Mr. Marshall was able to take his wife to the hospital where she was treated for serious injuries. Mr. Marshall is hoping to assist authorities in regards to this matter.”

Marshall’s rep declined to say whether he threw a punch or if he attempted to file a police report about his wife’s injuries.

The melee came less than a year after Marshall — traded yesterday from the Dolphins to the Bears — was allegedly stabbed by his wife.

“Both the Bears and Dolphins were aware of what occurred over the weekend,” Bears GM Phil Emery said in a statement reported by the Chicago Tribune. “We decided to move forward with the trade. We have high expectations for Brandon as a Bear.”

Marshall — who’s been busted at least six times — was involved in a New Year’s Eve 2006 fight in Denver that led to a teammate being fatally shot in a drive-by.