Photos: Floyd Mayweather Jr. versus Andre Berto

Floyd Mayweather Jr. blocks a punch by Andre Berto during their welterweight title fight Saturday night in Las Vegas.

Floyd Mayweather Jr. tries to evade a punch thrown by Andre Berto during their welterweight title bout on Saturday in Las Vegas.

Floyd Mayweather Jr. dodges a left from Andre Berto during their WBC/WBA welterweight title fight at MGM Grand Garden Arena.

Floyd Mayweather Jr. rests in his corner between rounds in his welterweight title bout against Andre Berto on Saturday night.

Andre Berto works against Floyd Mayweather Jr. against the ropes during their WBC/WBA welterweight title fight at MGM Grand Garden Arena.

Referee Kenny Bayless stops the fight to warn Floyd Mayweather Jr. and Andre Berto about their verbal exchanges during their WBC/WBA welterweight title fight at the MGM Grand Garden Arena.

Andre Berto, left, and Floyd Mayweather Jr. trade punches in the middle of the ring during their welterweight title bout Saturday night in Las Vegas.

Andre Berto tries to block a left jab from Floyd Mayweather Jr. during their welterweight title fight on Saturday night at the MGM Grand Garden Arena.

Floyd Mayweather Jr. lands an overhand right against Andre Berto during their WBC/WBA welterweight title fight Saturday.

Andre Berto, left, tries a left hook against Floyd Mayweather Jr. during their welterweight title bout in Las Vegas.

Floyd Mayweather Jr. drops to his knees at the end of his welterweight title bout against Andre Berto on Saturday.

Floyd Mayweather Jr., center, stands with referee Kenny Bayless, right, after defeating Andre Berto for the WBC/WBA welterweight titles.