Sebastian Fundora respects how Erickson Lubin has rebuilt his career following a devastating defeat nearly 4½ years ago.

The undefeated Fundora, who will battle Lubin on April 9 in Las Vegas, has taken notice from afar while Lubin methodically became a top contender again within the 154-pound division. Orlando’s Lubin has won six straight fights since Jermell Charlo knocked him out with one punch in the first round of their fight for Charlo’s WBC super welterweight title in October 2017 at Barclays Center in Brooklyn.

Lubin’s most recent win – a stoppage of Jeison Rosario – is commonly considered his most impressive performance since his loss to Charlo. The left-handed Lubin (24-1, 17 KOs) knocked out Rosario, a former IBF/IBO/WBA 154-pound champ, in the sixth round of their scheduled 12-rounder on the Gervonta Davis-Mario Barrios undercard June 26 at State Farm Arena in Atlanta.

The 6-foot-6 Fundora feels he had a hand in helping Lubin earn the victory that led to their “Showtime Championship Boxing” main event.

Rosario (21-3-1, 15 KOs) and Fundora sparred against each other in South Florida while the Dominican Republic’s Rosario prepared to box Lubin. Fundora was respectful toward Rosario during a recent interview with BoxingScene.com, but he made it clear that he had his way with the fighter Lubin beat before Rosario reached the ring for their WBC elimination match.

“To be honest with that,” Fundora said, “we had Rosario here for camp, for when he was training for ‘Hammer.’ … If you were there for the sparring sessions, you woulda saw it.”

Fundora (18-0-1, 12 KOs) was then asked if he feels he softened up Rosario for Lubin.

“Yeah, I gave him to Lubin, honestly,” Fundora replied. “I gave him to Lubin on a silver platter. To be nice, that’s the nice way to say it.”

However impressive Lubin’s victory over Rosario might’ve been, a confident Fundora knows his fight with Lubin will unfold far differently from how Rosario fared.

“We’re two different fighters,” said Fundora, a Coachella, California, native. “You can’t really compare the two. One’s right-handed, one’s southpaw. One’s taller than ‘Hammer,’ and then one’s not. So, it’s a different world.”

Caesars Sportsbook lists Fundora, 24, as a slight favorite to beat Lubin, 26. Their 12-round fight for the WBC interim super welterweight title will headline Showtime’s three-bout broadcast from Virgin Hotels Las Vegas (10 p.m. ET; 7 p.m. PT).

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