William Zepeda kept his foot on the pedal for all 12 rounds and outworked Lamont Roach Jr. to capture the vacant WBC lightweight championship by unanimous decision Saturday night at The Theater at Virgin Hotels in Las Vegas.
In a brilliant display of nonstop pressure and endurance, Zepeda's suffocating pace and high volume of punches gradually wore down Roach, who stood his ground and waited for his opportunities to land counters but couldn't slow Zepeda's activity.
The judges scored it 117-111, 117-111 and 118-110 for Zepeda (34-1, 27 KOs), who won his first major world championship with a career-best performance after suffering the first loss of his career against Shakur Stevenson last July.
Zepeda landed 218 of his 884 total punches, while Roach landed 153 of 591.
"Against Shakur, it was an exam I couldn't pass," Zepeda said through an interpreter. "And you know what? It was humbling. But we took the time, we came back stronger and worked on the weaknesses and came back, and now we're champion."
Zepeda won the title that became vacant when the WBC stripped Stevenson of the belt just days after he moved up to 140 pounds and became the WBO junior welterweight champion with a decisive victory over Teofimo Lopez.
Asked who he wants to fight next, Zepeda said his goal is to become the division's undisputed champion.
"I don't care who it is or when it is, put him in front of me and I'm going to beat him," he said.
Roach (25-2-3, 10 KOs) returned to the ring after consecutive majority draws in 2025 -- with Isaac "Pitbull" Cruz in December and with Gervonta "Tank" Davis in March.
Roach's big right hand caught Zepeda as he rushed in at several points in the fight, but Zepeda kept coming forward and continued to unload his flurry of punches.
Trailing late on the scorecards, Roach had flashes of success but couldn't put together combinations or land the one big punch that could turn the tide in the fight.
"We knew we had to watch out for that right hand," Zepeda said. "But all the punches that Roach threw, we had to respect every punch. We were ready for every counter."
In the co-main event, Raymond Muratalla (25-0, 17 KOs) easily outpointed former WBC junior lightweight titleholder Robson Conceicao (19-4-1, 9 KOs) in a one-sided decision to retain his IBF lightweight title.
Muratalla, ESPN's No. 2-ranked lightweight, dictated the pace from the start and was too fast, too strong and too accurate for Conceicao, who gamely absorbed several big shots and fought off his back foot most of the way because of Muratalla's pressure.
The judges scored it 118-110, 119-109, 119-109 for Muratalla, who said he plans to vacate his belt and move up to 140 pounds in pursuit of "any of the champions."
Saturday's main event and co-main event featured open scoring, with the judges' scorecards being revealed after Rounds 4 and 8.