Perez made no attempt to get to his feet as the referee waved an end the bout .
The fight ended in round 4 when Valdez landed with a left hand to the liver , followed by a right hand , which sent Perez down to all fours .
Perez made no attempt to get to Valdez 's feet as the referee waved an end the bout .
The fight ended in round 4 when Valdez landed with a left hand to the liver , followed by a right hand , which sent Perez down to all fours .