Pacquiao ups intensity as Rios breathes heavily

Manny Pacquiao trying to erase the smirk of Brandon Rios’ face with a flurry of power punches, throwing it as if it were jabs in the early going of the fourth round.

Rios tries for a clinch but Pacquiao too crafty to get out of Rios punches in the clinch.

The Mexican looking tired after four rounds of absorbing Pacquiao’s hits.