This time, it was far more definitive. Roach lost a one-sided unanimous decision to William Zepeda for the vacant WBC lightweight title on Saturday at Virgin Hotels Las Vegas on DAZN and TNT.

Roach (25-2-3, 10 KOs), a former WBA 130-pound titleholder, said Zepeda fought far differently from the fighter he was prepared to face. Zepeda, of San Mateo Atenco, México, last fought in July 2025, losing a unanimous decision to then-WBC lightweight champion Shakur Stevenson.

“Coming into the fight we just thought he was a one-trick pony,” Roach said in his post-fight interview. “He actually used his feet, as you can see. He was stepping back and kind of countering or not allowing me to get my counters off. He did it the whole fight. I had to switch a couple of things up, and I just didn’t succeed.”

It was a battle of Roach’s ability to box and counterpunch against Zepeda's relentless pressure and volume. Ultimately, the Washington, D.C., native struggled to corral and hold off the relentless Mexican southpaw.

Roach, 30, had his moments and landed some eye-catching shots, but they were too few and far between. Zepeda (34-1, 27 KOs) routinely pushed Roach back, overwhelmed him with his output and pace, and consistently landed the cleaner shots to the head and body.

Through nine rounds, Zepeda, 30, had already landed more punches than any opponent had against Roach in a fight, according to the broadcast. Zepeda outlanded Roach 218 to 153, according to CompuBox.

Zepeda won 118-110 and 117-111 twice across the judges’ scorecards.

“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. I take my hat off to they team. He was just one step ahead of me…They came ready. I came ready, but he was just the better man tonight.”