The lawsuit alleges Mayweather’s bodyguards attacked Anthony Cliff of Las Vegas near a valet parking stand at the Palms Casino Resort on March 27, 2010, after Mayweather accused Cliff of "disrespecting" him.

Mayweather’s bodyguards allegedly struck Cliff in the face, slamming his head into the ground. They then kicked him repeatedly in his back and side, the lawsuit says.

Mayweather’s attorney did not respond Monday to a request for comment. A spokesman for the Palms said casino officials do not comment on pending litigation.

Las Vegas police spokesman Jacinto Rivera said that an alleged battery at the Palms involving Mayweather and his entourage was reported, but the case was suspended because witnesses and casino video surveillance did not identify any suspects.

The lawsuit accuses Mayweather of assault and battery, intentional infliction of emotional distress and negligent hiring, training, supervision and retention of employees.

"At the end of the day there needs to be justice," said Afshin Tadayon, Cliff’s lawyer. "You can’t have people out there who do this sort of thing."

Cliff claims he first spotted the boxer inside the casino and tried to take his photo. He was told by a bodyguard that he could not do so. The lawsuit alleges Cliff walked away, but later ran into Mayweather again at the valet stand. Cliff asked someone in Mayweather’s entourage about a possible match between Mayweather and Pacquiao.

"Not only does Mr. Cliff want to see a fight against Mr. Pacquiao, but so do many boxing fans," Tadayon said. "So, it was just a question."

The inquiry seemingly infuriated Mayweather and his group, who surrounded Cliff and began threatening him, according to the lawsuit. Mayweather told Cliff he was disrespectful and allegedly gave his bodyguards a "thumbs down" gesture, "which was a sign for the bodyguards to attack," the lawsuit claims.

The Palms also was named in the 43-page lawsuit for allegedly failing to provide adequate security. Cliff claims the casino’s valet and security staff did nothing to help him during or after the alleged beating.

Pacquiao and Mayweather have come close to reaching a deal for potentially the most lucrative fight in boxing history multiple times, but they have yet to meet in the ring.

Mayweather has a history of court dealings.

Most recently, he failed to turn up for a court-ordered deposition in Las Vegas earlier this month in a federal lawsuit alleging he defamed Pacquiao.

Mayweather also faces felony charges stemming from a domestic argument and misdemeanor harassment and battery charges in separate cases.

The Las Vegas boxer is undefeated in 41 fights, having won titles in five divisions.