Photos: Timothy Bradley vs. Brandon Rios

Timothy Bradley Jr., right, works inside against Brandon Rios during their WBO welterweight title fight in Las Vegas on Saturday night.

Brandon Rios looks for an opening against Timothy Bradley during their WBO welterweight title bout Saturday.

Timothy Bradley connects against Brandon Rios during their WBO welterweight title bout Saturday night in Las Vegas.

WBO welterweight champion Timothy Bradley Jr. connects with a left jab against Brandon Rios during their title fight Saturday in Las Vegas.

Timothy Bradley Jr. connects to Brandon Rios’ face during their WBO welterweight championship bout on Saturday night in Las Vegas.

Timothy Bradley heads to a neutral corner after knocking down Brandon Rios during the ninth round of their WBO welterweight title bout Saturday.

Brandon Rios kneels on the mat after he was knocked down by Timothy Bradley during the ninth round of the WBO welterweight title fight Saturday.

Timothy Bradley celebrates after defeating Brandon Rios in a WBO welterweight title bout Saturday in Las Vegas.

WBO welterweight champion Timothy Bradley Jr. celebrates on the ropes after knocking out Brandon Rios.

Timothy Bradley Jr. has his WBO welterweight belt put on after defeating Brandon Rios with a knockout in the ninth round on Saturday night.

Vasyl Lomachenko, right, lands an overhand right against Romulo Koasicha during their WBO featherweight title bout on Nov. 7, 2015.  (John Locher / Associated Press)

Romulo Koasicha and Vasyl Lomachenko trade punches in the middle of the ring during their WBO featherweight title bout.

Vasyl Lomachenko lands a left to the head of Romulo Koasicha in the eighth round of their WBO featherweight title fight at the Thomas & Mack Center on Saturday.

Vasyl Lomachenko starts to celebrate as referee Robert Byrd counts out Romulo Koasicha in the 10th round of their WBO featherweight title fight on Saturday night in Las Vegas.