A compelling undercard will feature Mexican phenom Canelo Alvarez taking on future hall of famer Shane Mosley. Mayweather vs. Cotto happens Sat., May 5 live on pay-per-view. For more information on HBO Boxing, visit . br br Watch HBO Sports series and events online at HBO GO® br With HBO GO, you can watch your favorite HBO Sports series and events on your iPad® (), iPhone® () or Android™ () smartphone. Free with your HBO subscription through participating TV providers.