ARLINGTON, Texas — Brando Rios had trouble figuring out Omri Lowther, a slick boxer from Georgia.
The relentless lightweight contender continued to stalk him, though, patiently waiting to land a punch that would slow his opponent down and give him the advantage on the Manny Pacquiao-Antonio Margarito undercard Saturday at Cowboys Stadium.

It came in the fifth, a big right hand that hurt Lowther halfway through the round. Rios then landed several more hard punches, prompting the referee to stop the fight.

The official end came at 2:17 of the round.

Rios (26-0-1, 19 knockouts) now is in position to fight the winner of the Dec. 4 Urbano Antillion-Humberto Soto lightweight title fight early next year.

The Oxnard, Calif., resident was coming off a sensational victory over Anthony Peterson in September. Peterson, unbeaten at the time, was disqualified in the seventh round for repeated low blows in a fight he was losing badly.