The Money Man equalled Rocky Marciano's record in the familiar surroundings of the MGM Grand in Las Vegas, but insisted after he won't be attempting to break new ground with a 50th bout.
Berto struggled to land a meaningful punch as Mayweather danced his way to victory, interacting with the crowd mid-round and showboating towards the end.
The fight was everything boxing fans feared beforehand as Berto failed to impress the judges and a packed-out audience. "My career is over, that's official," Mayweather said afterwards.
