The Chelsea inside The Cosmopolitan of Las Vegas - A former valedictorian of his high school, Gary Antuanne Russell (15-0, 15 KOs) passed the biggest test of his career with flying colors, stopping the former world champion Viktor Postol (31-4, 12 KOs) abruptly in the tenth and final round of their super lightweight bout.

After pushing the action for most of the fight, Russell hurt Postol with a left uppercut in the tenth and followed up with a series of lefts and rights. With Postol against the ropes absorbing combinations, referee Mike Ortega intervened and waived it off at 2:31 of the tenth, much to Postol’s surprise, who shrugged his shoulders and seemed miffed at the stoppage. Russell kept his knockout streak alive while Postol dropped his second straight contest.

Russell was a 2016 U.S. Olympian who owned a 3-1 amateur record over current unbeaten welterweight Jaron Ennis, and he fought like one of the top contenders at 140 pounds on Saturday.

“The performance speaks for itself,” said Russell. “You see (Postol) went the distance with Terence Crawford, and I just stopped him. I believe I’m ready for another step-up fight.”

The two embraced in the ring when it was over, the respect between the fighters on full display. Postol fought on Saturday with his wife and their twin five-year old sons back home in Brovary, Ukraine in harm’s way with the Russian military invading the country.

“We’re in the hurt business,” Russell said of whether he felt compassion for his opponent. “I take my hat off to him. His country is literally at war but we’re in the squared circle doing our jobs. This man is coming to hurt him and I’m coming to hurt him.”

And Russell did that repeatedly on Saturday. Gary Russell Jr., the former titleholder who lost his belt last month, manned the corner on Saturday with their father Gary Sr. relegated to ringside for health reasons, and he told his younger brother to “break the will” of Postol throughout the bout. Russell obliged, fighting aggressively and continuously pinning Postol against the ropes.

Postol had some success with his right hand and his jab, especially in the ninth when he landed a thudding right , but Russell showed a granite chin and countered effectively and in the tenth he landed crisp combinations, showcasing his hand speed, leading to the stoppage, the first time Postol had ever been stopped. Russell led on the scorecards at the time of the stoppage by scores of 89-82, 89-82 and 88-83.

"I just couldn't do what I wanted to do in the ring,” said Postol. “My legs were not there and my arms were not there like I needed them to be. I've fought much better fighters than Gary Russell, but for some reason I wasn't able to perform to my abilities. I came here to win tonight. Unfortunately I wasn't able to achieve my goal."