Floyd Mayweather Jr. may have thoroughly beaten Manny Pacquiao Saturday at the MGM Grand Garden Arena to stay undefeated at 48-0, but just a few days after the mega bout, he's set for another battle as the mother of his three children filed a lawsuit Tuesday for defamation over his ex's recent comments about her, and a 2010 domestic violence attack in Las Vegas.

Mayweather's ex-girlfriend, Josie Harris, filed the lawsuit at the Los Angeles Superior Court Tuesday. According to ESPN, the fighter's lawyer Shane Emerick said he hasn't been served the case and declined to comment as of Wednesday.

The lawsuit is centered on comments Mayweather made in an interview with news anchor Katie Couric this April, wherein he said he was merely restraining Harris, and that she was on drugs at the time of the incident. The lawsuit claims Mayweather's comments were "utterly false." As noted by a CNN report, Harris is asking for $20 million in damages.

The best pound-for-pound boxer was arrested back in September 2010 after authorities said he punched Harris in his Las Vegas home, where he resided with his two sons and daughter.

Mayweather pleaded guilty to the charges, which were later reduced to a misdemeanor battery and two counts of harassment. He served two months of the original three-month sentence.

"Did I kick, stomp, and beat someone? No, that didn't happen. Did I restrain a woman that was on drugs? Yes, I did. So if they say that's domestic violence, then you know what? I'm guilty. I'm guilty of restraining someone," Mayweather told Couric.

Mayweather is fresh off the richest fight in boxing, and has already received $100 million as a partial payment for his efforts. Experts have projected that once the pay-per-view sales is figured out, the man who calls himself "Money" could make close to $200 million for one fight's work.