Erickson Lubin’s confidence is rightfully as high as it has been since before Jermell Charlo knocked him out in the first round of their 154-pound title fight in October 2017.

The strong southpaw produced his most impressive victory since Charlo caught him with one shot last month, when Lubin knocked out former champion Jeison Rosairo in the sixth round on the Gervonta Davis-Mario Barrios undercard at State Farm Arena. Lubin is 6-0 since Charlo beat him and is in prime position to fight the winner of the 154-pound title unification bout between Houston’s Charlo (34-1, 18 KOs) and Argentina’s Brian Castano (17-0-1, 12 KOs) on July 17 at AT&T Center in San Antonio.

“I’ll fight anybody,” Lubin said. “Anybody.”

When asked about boxing Charlo again, Lubin replied, “I said anybody. I’d love to fight Charlo. Anybody.”

The 25-year-old Lubin (24-1, 17 KOs) could’ve taken a safer fight than battling the Dominican Republic’s Rosario (20-3-1, 14 KOs) because he already was the WBC’s number one contender for Charlo’s championship. By knocking out Rosario, the Orlando, Florida, native validated that he deserves another title shot.

“I’m ready to work,” Lubin said. “I’m ready to keep getting better and taking the bigger fights and becoming champion.”

Lubin dropped Rosario twice in the sixth round before referee Jerry Cantu stopped their scheduled 12-round WBC elimination match.

Lubin’s left-right combination to Rosario’s body and then a jab knocked the ex-champion to his gloves and knees with just under two minutes remaining in the sixth round. Rosario reached his feet, but Lubin drilled him with a left hand to his head that floored Rosario again at the midway mark of the sixth round.

Cantu stopped their fight soon thereafter, at 1:42 of the sixth round.

“I had a tremendous camp and it just followed to the ring,” Lubin said. “You know, I worked hard. I’ve been working hard all year. I ain’t take no breaks. I ain’t take no shortcuts. You know, I felt tremendous. You know, I fought a big puncher. You know, I don’t want no tune-up fights. I said I ain’t want no tune-up fights. And, you know, I’m getting what I want. And, you know, I wanna show that I’m the best at 154 pounds. You know, I faced adversity at a young age and I’m just coming back, you know, better than ever.”

Rosario rocked Lubin with a left hand that made him take an awkward step with just over 20 seconds to go in the third round. Lubin recovered from that shot, though, and came back to ravage Rosario.

“It’s boxing,” Lubin said. “You get buzzed. He hit me with a clean shot. It wasn’t nothing that was gonna take me out or nothing. But, you know, I got hit with a good shot, I recovered well. I’m in shape, so I just came back and just, you know, weathered the storm.”

Charlo and Lubin have knocked out Rosario, a former IBF/IBO/WBA champion, in back-to-back bouts. If Charlo can conquer Castano and become boxing’s first undisputed 154-pound champion of the four-belt era, Lubin hopes he can secure an opportunity to avenge his lone loss.

Charlo has said that there’s no reason he should be forced to box Lubin again. If Charlo beats Castano and goes in a different direction, Lubin gladly would fight someone else for a 154-pound championship.

“You know, I’ll fight anybody, man,” Lubin said. “I’ve been saying this from day one, ever since I turned pro, I’ll fight anybody. So, that’s not even a question. You know, I’m ready to fight whoever. I’m always in the gym, I’m always working, I’m gonna keep getting better and keep giving these boys fits.”

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