Alvarado , the natural 140 - pounder , entered that fight as the undefeated WBO No. 1 junior welterweight contender .
Highlight knockout victories on Rios ' resume include Miguel Acosta , Anthony Peterson , Urbano Antillon , John Murray and Mike Alvarado ( twice ) .
Mike Alvarado , the natural 140 - pounder , entered that fight as the undefeated WBO No. 1 junior welterweight contender .
Highlight knockout victories on Rios ' resume include Miguel Acosta , Anthony Peterson , Urbano Antillon , John Murray and Mike Alvarado ( twice ) .