By Keith Idec

Liam Smith made Jaime Munguia earn his victory Saturday night.

Smith didn’t do enough to win, but the former champion from England landed plenty of shots to expose Munguia’s defensive flaws in their 12-round, 154-pound title fight in Las Vegas. The bigger, stronger, younger Munguia floored Smith in the sixth round, though, and won a unanimous decision to successfully make the first defense of his WBO junior middleweight title.

Mexico’s Munguia (30-0, 25 KOs) won on the cards of judges Tim Cheatham (116-111), Eric Cheek (119-108) and Dave Moretti (119-110) in the main event of HBO’s “Boxing After Dark” doubleheader from The Joint at Hard Rock Hotel & Casino.

The 29-year-old Smith demonstrated remarkable toughness by going 12 rounds against the hard-hitting Munguia. Liverpool’s Smith (26-2-1, 14 KOs) gave Munguia some trouble, particularly early in their entertaining fight, but he couldn’t hurt Munguia, who landed the more punishing punches.

“He was a tough opponent,” Munguia told HBO’s Max Kellerman through a translator. “I was always looking for the knockout, but he’s a tough opponent. … We went the distance, but it’s a learning experience. There’s no excuses. There’s nothing wrong with it.”

While he clearly won, the 21-year-old Munguia’s performance wasn’t as impressive as his previous appearance on HBO.

Munguia made a resounding debut on American television May 12 by destroying Sadam Ali in their 154-pound title bout in Verona, New York. The bigger, strong Munguia knocked down Ali four times on his way to a fourth-round technical knockout, but Ali (26-2, 14 KOs) is a natural welterweight who remained at 154 pounds for a title defense after upsetting Miguel Cotto on December 2 at Madison Square Garden.

Smith, however, is a former champion who has been a junior middleweight throughout his nine-year pro career. He withstood Munguia’s power much better than Ali.

Prior to Munguia beating him, Smith had lost only to Canelo Alvarez. Mexico’s Alvarez knocked out Smith with a brutal body shot in the ninth round of their September 2016 fight in Arlington, Texas.

“Canelo hits harder at super welterweight,” Smith said. “But he’s young. He’s probably gonna get more explosive. He’s 21 years of age. So he’s a good fighter and he’ll probably only get better and better.”

Smith had hoped to win back the WBO 154-pound championship from Munguia that he lost to Alvarez that night.

Smith, who was the WBO’s mandatory challenger at 154 pounds, was supposed to fight Ali on May 12. Munguia replaced him once Smith withdrew due to a skin condition that prevented him from training.

The challenger tried right up until the final bell to pull off an upset Saturday night, yet couldn’t do anything to hurt Munguia.

Smith drilled Munguia with an overhand right 1:05 into the 11th round. Munguia’s left hook caught Smith flush late in the 11th round.

Smith landed enough punches in the 10th round to make it competitive, but he couldn’t hurt Munguia.

With 2:24 to go in the ninth round, Munguia blasted Smith with a left hook to the body. Mora called time with 1:24 to go in the ninth to fix the tape on one of Munguia’s gloves.

Despite Munguia drilling him with head and body shots, Smith fired back and landed right hands and left hooks of his own late in the ninth round.

Smith landed three left hands in a successful sequence with under a minute to go in the eighth round. Munguia and Smith got tangled up and went crashing the canvas later in the eighth.

After suffering a sixth-round knockdown, Smith made the seventh round competitive. Munguia landed the harder shots in that round, though, and appeared to win it.

A quick left hook by Munguia knocked Smith backward and to the canvas with 35 seconds left in the sixth round. The game Smith got up, fought back and made it to the end of the round.

Munguia drilled Smith with a left hook to the body and quickly followed up with a left hook to the head early in the fifth round. Smith hammered Munguia with an overhand right with 36 seconds remaining in the fifth.

Munguia drilled Smith with a left hook about 55 seconds into the fourth round. Smith’s best punch of the fourth round was the straight right hand he landed with just over 30 seconds to go in it.

Smith moved Munguia into the ropes by landing a left hand early in the third round. A left hook by Smith knocked Munguia off balance with around two minutes to go in the third.

Smith then connected with a straight right hand when there was just under 30 seconds to go in the third. Smith smiled at Munguia after landing that shot.

Munguia’s hard left to the body affected Smith about a minute into the second round. Smith landed multiple right hands both before and after Munguia’s hard body shot.

Smith landed a right-left combination Munguia acknowledged by nodding his head with just over a minute remaining in the first round. Smith also landed a right uppercut later in the first round.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.