The improved, relentless Mexican southpaw’s pressure and vaunted volume punching helped him out-point Lamont Roach unanimously in their 12-round fight for that vacant championship at Virgin Hotels Las Vegas. Roach fought defending champions Gervonta Davis and Isaac Cruz to majority draws in each of his two previous bouts, but he didn’t deal with the well-prepared Zepeda nearly as effectively as Shakur Stevenson handled him a year ago.

Judges Tim Cheatham (117-111), Erik Cheek (117-111) and David Sutherland (118-110) all scored at least nine rounds for Zepeda.

A refreshed Zepeda (34-1, 27 KOs) fought for the first time since Stevenson comfortably beat him on all three scorecards in their fight for the WBC lightweight crown a year ago at Louis Armstrong Stadium in Queens, New York. His decisive defeat to Stevenson (25-0, 11 KOs), a four-division champion ranked No. 3 on The Ring’s pound-for-pound list, inspired Zepeda to prove he is better than he demonstrated that night against another top opponent.

“Against Shakur, it was an exam I couldn’t pass,” Zepeda told DAZN/TNT announcer Chris Mannix in the ring after unofficially throwing 884 punches. “But you know what? It was humbling. But we took the time, we came back stronger, worked on the weaknesses and came back, and now we’re champion.”

The No. 1-rated Zepeda, 30, and the second-ranked Roach, also 30, fought for the WBC lightweight title that was stripped from Stevenson when he refused to pay a reported $120,000 fee for the WBC to allow him to face Teofimo Lopez in a WBO junior welterweight championship match January 31 at Madison Square Garden in New York.

Roach (25-2-3, 10 KOs) lost for the first time since Jamel Herring beat him by unanimous decision in November 2019 in their 12-round fight for Herring’s WBO junior lightweight title. The improved Roach was praised for his performance versus Davis (30-0-1, 28 KOs), who he would’ve upset had referee Steve Willis counted a knockdown for him when Davis took a knee in the ninth round 17 months ago at Barclays Center in Brooklyn.

Zepeda didn’t allow Roach to get into that type of comfort zone.

Roach fought off his front foot during the 10th round, when Zepeda threw fewer punches than usual. The former WBA 130-pound champ had some success in the 11th and 12th rounds as well, but it wasn’t nearly enough to approach Zepeda on the scorecards.

A combination by Zepeda to Roach’s head and body knocked him off balance in the final minute of the ninth round. Roach looked like a beaten fighter when he sat on his stool following those three minutes of action.

Zepeda continued to wear down Roach in the seventh and eighth rounds, when he continuously connected with punishing punches to Roach’s head and body. All three judges had Zepeda ahead through eight rounds (78-74, 77-75, 77-75).

Zepeda built on his lead by out-working Roach in the fifth round, but Roach caught him with two eye-catching left hooks to his head in the sixth.

Zepeda’s pressure and volume helped him pick Roach apart for much of the fourth round. Once it ended, open scoring informed them that Zepeda was ahead on two scorecards entering the fifth round (39-37, 39-37, 38-38).

Trading with Zepeda enabled him to catch Roach with clean shots in the first half of the third round.

Roach’s right hand knocked Zepeda backward with just under 50 seconds to go in the second round, which highlighted his ability to make Zepeda pay for coming forward and not being mindful of defense. A left hook by Roach in the first round was the cleanest punch of the opening three minutes as well.

Roach didn’t have as much success later in their fight and commended Zepeda’s performance. Roach expressed surprise that Zepeda wasn’t the “one-trick pony” he expected and showed better footwork than anticipated.

“Zepeda was well prepared tonight,” Roach said. “Him and his team, they had a tremendous game plan and he put it into place. No excuses. You know, I take my hat off to they team. He was just one step ahead of me.”