Justin Bieber, left, and Lil Wayne gather inside the ring before a 152-pound title fight between Floyd Mayweather Jr. and Canelo Alvarez, Saturday, Sept. 14, 2013, in Las Vegas. (AP)
Elon Musk, right, is seen before a 152-pound title fight between Floyd Mayweather Jr. and Canelo Alvarez, Saturday, Sept. 14, 2013, in Las Vegas. (AP)
John Voight applauds as Floyd Mayweather Jr. and Canelo Alvarez enter the ring for their 152-pound title fight, Saturday, Sept. 14, 2013, in Las Vegas. (AP)
Busta Rhymes arrives at the VIP Pre-Fight Party for the One: Mayweather vs. Canelo Fight at the MGM Grand Garden Arena on Saturday, Sept. 14, 2013 in Las Vegas. (Invision/AP)
Lil Wayne performs inside the ring before a 152-pound title fight between Floyd Mayweather Jr. and Canelo Alvarez, Saturday, Sept. 14, 2013, in Las Vegas. (AP)
Jon Voight, left, Dash Mihok and Pooch Hall arrive at the VIP Pre-Fight Party for the One: Mayweather vs. Canelo Fight at the MGM Grand Garden Arena on Saturday, Sept. 14, 2013 in Las Vegas. (Invision/AP)
Diddy Combs is seen during a 152-pound title fight between Floyd Mayweather Jr. and Canelo Alvarez, Saturday, Sept. 14, 2013, in Las Vegas. (AP)
Danny Trejo & George Lopez arrive at the VIP Pre-Fight Party for the One: Mayweather vs. Canelo Fight at the MGM Grand Garden Arena on Saturday, Sept. 14, 2013 in Las Vegas. (Invision/AP)
LL Cool J & wife Simone Smith arrive at the VIP Pre-Fight Party for the One: Mayweather vs. Canelo Fight at the MGM Grand Garden Arena on Saturday, Sept. 14, 2013 in Las Vegas. (Invision/AP)
Floyd Mayweather Jr., left, poses for photos with Justin Bieber after defeating Canelo Alvarez during a 152-pound title fight, Saturday, Sept. 14, 2013, in Las Vegas. (AP)