Jaime Munguia replaces Liam Smith as challenger to titlist Sadam Ali

Barely 24 hours after Liam Smith withdrew from his fight against junior middleweight world titlist Sadam Ali, Golden Boy Promotions secured a replacement challenger: Jaime Munguia.

Former junior middleweight titleholder Smith, suffering from a skin condition that has left him unable to train for more than a week, withdrew from his mandatory title shot against 154-pound titlist Ali on Friday.

On Saturday evening, Golden Boy Promotions president Eric Gomez told ESPN that he had secured Munguia to step in to face Ali on May 12 (HBO, 10 p.m. ET/PT) at the Turning Stone Resort Casino in Verona, New York.

"Munguia is in," Gomez said. "We're delighted to save the show. Sadam Ali is willing to fight any and all comers. Munguia is probably more dangerous [than Smith]. He's undefeated, and he's a huge puncher."

With Smith (26-1-1, 14 KOs), 29, of England, sidelined for the next few weeks and Ali unable to train or fight during Ramadan, which will be observed May 14 to June 15, Golden Boy wanted to find a new opponent to face Ali on May 12 rather than delay his next fight deep into the summer.

Munguia (28-0, 24 KOs), 21, of Mexico, one of boxing's top prospects, was recently offered a short-notice fight with unified middleweight champion Gennady Golovkin as Canelo Alvarez's replacement on May 5. But given Munguia's lack of experience against top opponents, Golovkin's stature as one of boxing's most devastating punchers and that Munguia would have to move up in weight for the fight, the Nevada State Athletic Commission said it would not approve the bout. Against Ali, Munguia will be facing an opponent his own size and one not nearly as devastating with his power.

Even though Munguia did not get the fight with Golovkin, he was scheduled to fight on May 12 on a Zanfer Promotions card in Tijuana, Mexico, so he has been training.

Ali (26-1, 14 KOs), 29, of Brooklyn, New York, won the title on Dec. 2 when he won a unanimous decision against Puerto Rican legend Miguel Cotto to send him into retirement. He will be making his first defense against Munguia.

In the May 12 cofeature, junior featherweight world titleholder Rey Vargas (31-0, 22 KOs), 27, of Mexico, will defend his title for the third time when he faces Azat Hovhannisyan (14-2, 11 KOs), 29, a native of Armenia fighting out of Los Angeles.