PHOENIX – Rafael Espinoza landed the right hand flush to Robeisy Ramirez’s right eye, and when Ramirez turned away, raising his right hand, Espinoza was lost for answers.

A second later, he found out. Ramirez could no longer fight, claiming double vision in the eye, and Espinoza had retained his WBO featherweight belt.

In front of 8,438 fans Saturday night at Footprint Center, Ramirez said Espinoza had injured his eye with elbows earlier in the fight that went undisciplined.

“I complained to the ref about it and he didn’t stop it,” Cuba’s Ramirez said.

When Espinoza’s sixth-round punch landed, the vision was dangerously obscured, Ramirez said, and the area above and under his right eye began swelling immediately.

Ramirez said his thoughts turned from winning the fight – he was ahead 48-47 on two scorecards and behind 49-46 on the other – to preserving his vision.

“I had to make the decision I made for my health. I had double vision,” Ramirez said. “I cannot see out of my right eye.”

Espinoza 26-0 (22 KOs) celebrated, expressing confidence that the fight was trending in his favor. Manny Robles, Espinoza's trainer, told BoxingScene afterward he thought Ramirez either quit or "was looking for a way out."

“I was just doing my job. Obviously, I caught him,” Espinoza said. “I was barely getting started. Honestly, I think the pressure and the rest of the rounds were going to be very difficult for him. This means that he felt my power. He felt my hand. Perhaps he thought that he wouldn’t be able to handle it. But it happened. I won.”

Espinoza, 30, originally won the belt by virtue of his 12th-round knockdown of Ramirez in their December 2023 first bout. He followed with a fourth-round TKO victory over Sergio Chirino Sanchez in June, and officials at his promotional company, Top Rank, openly speculated this week that Espinoza’s 6-feet-1 frame begs for a move up to super-featherweight.

Espinoza said he's seeking unifications in his division that counts Brandon Figueroa, Angelo Leo and Nick Ball as champions. If he can't get those, he'll move up, he said.

“I want to be a legend. I want to fight anybody,” Espinoza said.

The champion opened the fight leaning on his physical advantages, relying on his reach to land jabs and seek openings while Ramirez was content to find openings on the champion’s midsection.

Ramirez 14-3 let valuable time vanish while planning for openings while Espinoza could afford to be assertive because of his size, pressing forward to snap a hard right to the head in the second round and add a sharp left uppercut to the face.

The plotting paid dividends in the third as Ramirez planted hard rights to the face that earned the champion’s respect as he winked toward the Cuban after absorbing the blows.

Exchanges during the fourth made it look like the combatants were settling in to go the distance.

Espinoza’s ability to deliver combinations and creativity to go low to land an uppercut helped him shine through the competitive frames, and his ability to land that final right cleanly ended the night 12 seconds into the sixth.