ALLENTOWN, Pennsylvania – A showdown with Gervonta Davis is the lightweight fight on which Gary Russell Jr. is most focused at the moment.

Russell is very confident he’d become the first fighter to defeat Davis in what would be a high-profile boxing event in the Baltimore-Washington, D.C. area. The long-reigning WBC featherweight champion has hardly forgotten, though, about the lightweight champion who dealt Russell what remains his lone professional loss 5½ years ago.

“I want a rematch with Vasiliy Lomachenko,” Russell said Sunday morning, after successfully defending his 126-pound crown against Tugstsogt Nyambayar. “I don’t wanna do it for the fans. I don’t wanna do it for the media. I wanna do it for myself. I’ve got too much integrity to let something like that go. I’ve gotta get [that] back.”

Lomachenko beat Russell by majority decision in their 12-round, 126-pound championship match in June 2014. The WBO ordered that featherweight championship bout between Lomachenko and Russell, who lost eight rounds on two scorecards (116-112, 116-112) and boxed the Ukrainian southpaw to a draw on the third card (114-114).

The 31-year-old Lomachenko (14-1, 10 KOs) since has moved up to win world titles in the junior lightweight and lightweight divisions. The two-time Olympic gold medalist is headed for a 135-pound title unification fight in the spring against unbeaten IBF champion Teofimo Lopez (15-0, 12 KOs).

Russell, meanwhile, seems intent to give up his WBC featherweight title to jump up two weight classes and pursue bigger fights that interest him in the lightweight division.

The 31-year-old Russell (31-1, 18 KOs) has held his 126-pound title since stopping Mexico’s Jhonny Gonzalez in the fourth round of their March 2015 bout in Las Vegas. Only one boxer, WBC heavyweight champ Deontay Wilder, has held his title longer than Russell, of Capitol Heights, Maryland.

After out-classing Mongolia’s Nyambayar (11-1, 9 KOs) in a mandated match he comfortably won by unanimous decision, Russell doesn’t think there are any featherweight fights that’ll keep him in the division he has occupied since he turned pro 11 years ago. Leo Santa Cruz (37-1-1, 19 KOs) hasn’t shown interest in battling Russell in a 126-pound title unification fight and there aren’t any opponents at 130 pounds that intrigue Russell.

That’s why he has targeted Baltimore’s Davis (23-0, 22 KOs) and Lomachenko at lightweight.

When asked if he thinks Lomachenko would fight him again, Russell replied, “It’s possible. I hope he would do [it]. I hope he do.”

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