Brandon Rios doesn't make weight

NEW YORK -- Brandon Rios, unable to make 135 pounds at Friday's weigh-in, lost his lightweight title on the eve of his fight with England's John Murray.

The fight, the co-feature on the Miguel Cotto-Antonio Margarito II undercard at Madison Square Garden on Saturday night (HBO PPV, 9 ET, $54.95), will still go on. However, the "regular" version of the WBA title will remain vacant if Rios wins. If Murray wins, he claims the belt. If it's a draw, the title will also remain vacant.

Murray's team threatened to call off the fight, but eventually extracted concessions from Rios. He will pay Murray $20,000 from his $325,000 purse, a nice increase for Murray, who is due $50,000 plus a piece of British television revenue.

Also, to prevent Rios from blowing up in weight overnight, Murray's camp insisted that Rios not weigh more than 147 pounds at 9 a.m. ET Saturday. At the morning weigh-in, Rios weighed 146.4 pounds, so the fight is on.

"I think that may play to my advantage, but I'm just going to concentrate on myself," Murray said. "I'll let him worry about himself. I'm just going to stay on my game and do my business. I'm not upset at all. I'm just focused on doing my business (Saturday) night.

"We had already prepared to take him into the deep waters. This is a great opportunity for a guy like me. Fights like this are the fights that I want. I want to be in the center of the ring, hammering away to see who is going to be left standing, him or me."

Rios' manager, Cameron Dunkin, said he learned Friday that Rios consumed nothing -- save for four ounces of water on Wednesday -- in the previous five days leading up to the weigh-in.

Rios was clearly having trouble making weight all week, looking extremely drawn. When he first stepped on the scale, he was 136.6 pounds, well over the 135-pound lightweight limit. With an hour to try to lose the weight, he could not do it. On his second attempt he was 135.6 and about a half hour later he had gone up to 136.6. At that point, the title was vacated and the sides cut the deal.

"He's been in a colder climate than he's used to and that probably hurt him trying to make weight," Carl Moretti of Top Rank, Rios' promoter, said of the Southern California fighter. "He's a big 135-pounder. He just couldn't get down. The question is what happens Saturday night and in the future? I think it's too soon to say that he's done at 135 but he could be. We'll have to talk about with him and his team, see if maybe he went about making weight the wrong way. But he looked drained, very drained."

Rios, 25, won the belt in comeback fashion in February, knocking out Miguel Acosta in the 10th round. He defended the title in July with a third-round knockout of California rival Urbano Antillon.

With Rios (28-0-1, 21 KOs) the favorite against Murray -- before the weight issues -- Top Rank had been looking ahead and eyeing a match between him and former featherweight titlist Yuriorkis Gamboa, who is moving up in weight. However, those plans could be on hold if Rios moves up to junior welterweight after the problem making lightweight.

Murray (31-1, 18 KOs), 26, made came inside the limit, weighing 134.75 pounds. He is coming off his first career defeat, an eight-round TKO loss to countryman Kevin Mitchell in a competitive fight.

Dan Rafael is ESPN.com's boxing writer.