Marcos Maidana, left, from Argentina, trades punches with Floyd Mayweather Jr. in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
Marcos Maidana, left, from Argentina, throws a left at the head of Floyd Mayweather Jr. in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
Marcos Maidana, left, from Argentina, trades blows with Floyd Mayweather Jr. in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
Floyd Mayweather Jr., right, connects with a right to the head of Marcos Maidana, from Argentina, in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Floyd Mayweather Jr., right, trades punches with Marcos Maidana, from Argentina, in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Floyd Mayweather Jr. sits in his corner during his WBC-WBA welterweight title boxing fight against Marcos Maidana Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Floyd Mayweather Jr., right, connects with a right to the head of Marcos Maidana, from Argentina, in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
Marcos Maidana, center, from Argentina, knocks Floyd Mayweather Jr. through the ropes in their WBC-WBA welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. At left is referee Tony Weeks. (AP Photo/Eric Jamison)
Marco Periban, right, from Mexico, and J'Leon Love, from Las Vegas, exchange blows in their WBA super middleweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Marco Periban, right, from Mexico, and J'Leon Love, from Las Vegas, trade blows in their WBA super middleweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Adrien Broner, left, from Cincinnati, Ohio, lands a right to the head of Carlos Molina, from Norwalk, Calif., in their WBA super lightweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Adrien Broner, left, from Cincinnati, Ohio, throws a left to the body of Carlos Molina, from Norwalk, Calif., in their WBA super lightweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Adrien Broner, right, from Cincinnati, Ohio, trades blows with Carlos Molina, from Norwalk, Calif., in their WBA super lightweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Adrien Broner, left, from Cincinnati, Ohio, talks with Carlos Molina, from Norwalk, Calif., after winning their WBA super lightweight title boxing fight by unanimous decision Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Carlos Molina is embraced by his corner after his unanimous decision defeat against Adrien Broner in their WBA super lightweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
Adrien Broner celebrates his unanimous decision victory over Carlos Molina in their WBA super lightweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Eric Jamison)
England's Amir Khan, left, lands a right against Luis Collazo in their silver welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
England's Amir Khan is hoisted by his corner after defeating Luis Collazo in their silver welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
=England's Amir Khan is hoisted by his corner after defeating Luis Collazo in their silver welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)
England's Amir Khan, right, connects with a hard right to the head of Luis Collazo in their silver welterweight title boxing fight Saturday, May 3, 2014, in Las Vegas. (AP Photo/Isaac Brekken)