Recently-retired Floyd Mayweather Jnr was provoked into a shouting match over Gennady Golovkin by a heckler in New York City.
The 40-year-old briefly came out of retirement in late August to beat Conor McGregor, seeing off the Irishman in the 10th round of the bout in Las Vegas.
Maywather, who had attended the New York Knicks basketball fixture, was accused by the heckler of "running away" from Kazakh fighter Golovkin.
By defeating McGregor, Mayweather secured a 50-0 unbeaten record as a professional, but exchanged a war of words with the heckler on Monday night.
Defending himself from the tirade of verbal insults, Mayweather reportedly claimed that he wasn't afraid of Golovkin.