Brandon Rios barely remained unbeaten with a split-decision victory over Richard Abril on Saturday night after failing to make weight for the lightweight bout.

Rios (30-0-1, 22 KOs) seemed sluggish and wooden for long stretches of the bout after the former lightweight champion came in two pounds over the 135-pound limit Friday.

The decision appeared to upset many fans at the Mandalay Bay Events Center. Although Abril (17-3-1) fights in an unattractive style, he appeared to control several rounds with superior precision and strategic clinches.

Judge Jerry Roth scored the fight 116-112 for Rios, and Glenn Trowbridge favored Rios 115-113. Adalaide Byrd scored it 117-111 for Abril.

The mercurial Rios, a rising star in the Top Rank stable of fighters, lost his shot at a $50,000 winner's bonus and the chance to reclaim his title when he failed to make weight in his second straight fight. Rios also lost his belt on the scales last December, missing weight in New York before stopping Britain's John Murray.

Abril, a Cuban who fights out of Miami, was a replacement opponent for Rios after fellow Cuban Yuriorkis Gamboa dropped out of the matchup last month in a contract dispute, turning down what promoters said was a seven-figure payday. Abril won the interim WBA belt last October by beating Miguel Acosta, but this decision ended his five-fight winning streak.

Abril seemed more proficient from the opening bell, peppering Rios with shots and combinations. Rios became more physical in the later rounds, butting his way inside Abril's defense with his head, but Abril frequently wrapped up and minimized the damage.

Rios' left eye became puffy in the late rounds, and he kept forcing his way inside with little result. Both corners raised their fighters in the air after the bout.

On the undercard of a two-site pay-per-view card also featuring Juan Manuel Marquez's ring return against Sergey Fedchenko in Mexico City, Mike Alvarado remained unbeaten and in line for a 140-pound title shot with a tidy unanimous decision over Mauricio Herrera.

Rios intended to move up to 140 pounds in his next bout, and was hoping for a shot at Marquez this summer at Cowboys Stadium. His weight failures and a lackluster victory could affect those plans.