ALLENTOWN, Pennsylvania – Gary Russell Jr. walked away from his fight against Tugstsogt Nyambayar with the same feeling he had after he beat Joseph Diaz Jr.

Russell out-boxed Nyambayar, too, but the previously unbeaten Mongolian impressed Russell in their 12-round featherweight title fight Saturday night at PPL Center. The 2012 Olympic silver medalist’s toughness struck Russell, who thinks Nyambayar can learn from this first professional defeat and, like Diaz, come back to win a world title.

“He was definitely one of the better fighters that I competed against,” Russell told a group of reporters following his unanimous-decision win. “I feel like he would give any of these guys in the upper echelon a run for their money. He was definitely good, just like a Jo Jo Diaz. I take my hat off to Jo Jo Diaz. I think if [Nyambayar] was to stay focused, once again, he would become a world champion, just like Jo Jo Diaz did.”

Less than two years after Russell defeated Diaz by unanimous decision, Diaz out-worked favored former 130-pound champion Tevin Farmer to take the IBF junior lightweight championship from him in another 12-rounder January 30 in Miami. Like Nyambayar, Diaz has an Olympic pedigree and has lost only to Russell.

The 27-year-old Diaz (31-1, 15 KOs), of Downey, California, won four fights between his loss to Russell in May 2018 and his victory over Philadelphia’s Farmer (30-5-1, 6 KOs, 1 NC) last month. He was the mandatory challenger for Russell’s title when they fought, as was Nyambayar, who lost to the faster, more experienced Russell by wide distances on all three scorecards (118-110, 117-111, 116-112).

Diaz moved up from featherweight to junior lightweight before becoming a world champion. The 27-year-old Nyambayar (11-1, 9 KOs) intends to remain at featherweight for the foreseeable future.

Versus Russell, Nyambayar didn’t throw enough punches and was too reliant on his right hand, which the defensively effective Russell slipped countless times.

“It was definitely the kind of fight I expected,” Russell said. “I knew I was fighting a tough competitor. You know, he had everything to gain and nothing to lose. He brought his physical best. We knew he was gonna be strong, but I felt like my hand speed, my ring generalship, my boxing IQ [would be the differences]. That was exactly what happened. I kept the jab in his face. He couldn’t get past it. On the back half of the fight, I told myself I was gonna lock my hands up and start walking forward and dictating the action and pressing the action, and that’s exactly what we did.”

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