Floyd Mayweather vs. Robert Guerrero

Floyd Mayweather Jr. gives vanquished challenger Robert Guerrero a pat on the head as they talk after their WBC welterweight title fight on Saturday night.   (Rick Bowmer / Associated Press)

Robert Guerrero listens to his father and trainer, Ruben Guerrero, as he rests after the ninth round of his WBC welterweight title bout against Floyd Mayweather Jr. on Saturday night in Las Vegas.   (Isaac Brekken / Associated Press)

Floyd Mayweather Jr. sends Robert Guerrero backward with a right hand in the fourth round of their WBC welterweight bout on Saturday night in Las Vegas.   (Rick Bowmer / Associated Press)

Robert Guerrero backs Floyd Mayweather Jr. to the ropes during their WBC welterweight title bout on Saturday night in Las Vegas.   (Al Bello / Getty Images)

Floyd Mayweather Jr. lands a left jab against Robert Guerrero in the fourth round of their WBC welterweight championship bout on Saturday night at the MGM Grand Garden Arena in Las Vegas.   (Isaac Brekken / Associated Press)

Floyd Mayweather Jr. connects with a combination against Robert Guerrero during their WBC welterweight championship bout on Saturday night at the MGM Grand Garden Arena.   (Ethan Miller / Getty Images)

Floyd Mayweather Jr. slips a punch by Robert Guerrero in their WBC welterweight title fight at the MGM Grand Garden Arena on Saturday night.   (Al Bello / Getty Images)

Floyd Mayweather Jr. clinches the head of Robert Guerrero during their WBC welterweight championship fight on Saturday night.   (Al Bello / Getty Images)

Floyd Mayweather Jr. tries to evade a punch by Robert Guerrero, who lands a right to the champion’s chest, during their WBC welterweight title bout on Saturday night.   (Al Bello / Getty Images)

Floyd Mayweather Jr. reacts as Robert Guerrero tries to throw a punch while referee Robert Byrd asks them to break during their WBC welterweight title fight on Saturday night.   (Ethan Miller / Getty Images)

Floyd Mayweather Jr. ducks a punch by Robert Guerrero in the third round of their WBC welterweight title fight on Saturday night at the MGM Grand Garden Arena in Las Vegas.  (Rick Bowmer / Associated Press)

Robert Guerrero lands a right against Floyd Mayweather Jr. in the third round of their welterweight title bout on Saturday night in Las Vegas.   (Isaac Brekken / Associated Press)

Robert Guerrero presses the attack against Floyd Mayweather Jr. in the first round of their WBC welterweight championship bout on Saturday night at the MGM Grand Garden Arena in Las Vegas.   (Isaac Brekken / Associated Press)

Floyd Mayweather Jr. sends Robert Guerrero reeling with an overhand right to the head in their WBC welterweight title fight on Saturday night at the MGM Grand Garden Arena.   (Al Bello / Getty Images)

Challenger Robert Guerrero approaches the ring before the WBC welterweight championship bout against Floyd Mayweather Jr. on Saturday night in Las Vegas.   (Al Bello / Getty Images)

Floyd Mayweather Jr. enters the ring for the WBC welterweight title fight against Robert Guerrero on Saturday night.   (Al Bello / Getty Images)