MINNEAPOLIS – Brian Mendoza’s career-changing, fifth-round knockout of Jeison Rosario on Saturday night thrust him into a position in which Mendoza always believed he belonged.

The Albuquerque native now can confidently call out opponents in the junior middleweight and middleweight divisions.

“PBC is poppin’ at 154 and 160,” Mendoza told BoxingScene.com following the most impressive victory of his career. “Give me the best. I don’t care. Really, I don’t care. If you guys want names, I’ve got names. But I don’t care. I want titles. Right now, [Jermell] Charlo’s unified, so I want him. But whoever I’ve gotta get out of the way to get him, I’ll do it. Just put him in front of me.”

The 28-year-old Mendoza made his middleweight debut against Rosario, a former IBF/IBO/WBA 154-pound champion. He had boxed exclusively at welterweight and junior middleweight before the Las Vegas resident accepted this 10-round middleweight match against Rosario on only about 10 days’ notice.

The Dominican Republic’s Rosario (23-4-1, 17 KOs) was scheduled to face emerging Cuban southpaw Yoelvis Gomez (6-0, 5 KOs). Gomez sustained an injury to his right wrist while training and Mendoza immediately replaced him.

Mendoza (21-2, 15 KOs) took the taller Rosario’s hardest punches without incident in what was Rosario’s fourth straight fight at middleweight or super middleweight. His performance cemented Mendoza’s belief that he is ready for any top opponent.

“Whatever opportunity that comes up, I’m ready to jump on it,” Mendoza said. “I feel amazing. Whether it’s at 154 or 160, I just want world titles. I’ve always believed I’m a champion, and now I feel like the experience is finally paying off. And it’s time.”

Well aware that Rosario is susceptible to body shots, Mendoza dropped him with a perfectly placed left hook to the body when there was just under a minute remaining in the second round.

Rosario reached his feet just in time to beat referee Mark Calo-oy’s count. Then he held and moved his way to the end of the second round.

Mendoza’s ravaging right uppercut was too much for Rosario to overcome early in the fifth round, though. Rosario got up again, but he was so disoriented that he fell back to the canvas and caused Calo-oy to halt the action 35 seconds into the fifth round.

“If you can’t take body shots, you can’t be in the ring with Brian Mendoza,” Mendoza said. “That’s been a thing since the amateurs. Even as a pro, a lot of my knockouts, some were to the body and then I finished up top. I’m gonna slow you down to the body and then I’m gonna open you up. He knows he’s open to the body, so he started making some adjustments, caught me with some shots and then I came with that big uppercut.”

Losing a 10-round unanimous decision to unbeaten 154-pound contender Jesus Ramos (19-0, 15 KOs) in September 2021 didn’t discourage Mendoza from returning to the gym to hone his craft with respected Cuban trainer Ismael Salas. Mendoza remained motivated to prove he’s better than he looked against Ramos and in an eight-round, split-decision defeat to Larry Gomez (then 9-1) in November 2019.

“Since April, I’ve been training with a pretend opponent in mind, just ready to prove everybody wrong,” Mendoza said. “I’ve always known I’ve been something special. I started boxing at 16. I needed time to progress. I just turned 28 this year. I’m in my prime. This was an ex-world champion. If you look back at his losses, it’s [Erickson] Lubin, a phenomenal fighter, Charlo, c’mon. And now it’s Brian Mendoza added to that list. I want a shot at all these guys.”

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