QUEBEC CITY — When people say that boxing is a young man’s sport, they usually have nights like tonight in mind.

Christian Mbilli, a young, hungry and powerful fighter waiting for his opportunity, stalked away at a respected but aging former title challenger in Sergiy Derevychaneko. Derevyanchenko, nine years the senior of Mbilli, knew what he needed to do to slow the relentless Mbilli, but at age 38, his body didn’t respond the way it once had.

It’s the way boxing has been since its earliest days. Just as the elder fighters had built their names off past prime fighters on their way up, so is the way many of them become stepping stones to the next generation.

Mbilli scored the breakout win so far of his young career on Saturday, defeating the three-time title challenger by unanimous decision at Centre Videotron in Quebec City, Canada. The scores were 100-90, 99-91 and 98-92, all for Mbilli (28-0, 23 knockouts), a Cameroon born, France raised slugger who has become a fan favorite in the French speaking Canadian province of Quebec.

Mbilli set the tone for the fight in the first 30 seconds, landing a heavy right which Derevyanchenko took well. But as Mbilli began to bang away at Derevyanchenko’s body, it opened up opportunities to the head, including an overhand right that wobbled Derevyanchenko momentarily in the second round. By the third round, the consistent pounding from Mbilli had swollen up Derevyanchenko’s face.

As if Derevyanchenko needed any more of a mountain to climb, his left hand became inoperable by the fourth due to a suspected bicep injury. The injury meant that, not only could Derevyanchenko not keep Mbilli off with his jab, he also couldn’t raise his glove up to block the right hands which had been landing consistently on Derevyanchenko since the opening round. At the end of the fourth, Derevyanchenko motioned to his left arm and shook his head as he walked back to his corner.

Photo by Mikey Williams/Top Rank

It would have been understandable if Derevyanchenko would have recognized that he no longer had a competitive chance in the fight due to the injury and packed it in, but that’s not the way the Brooklyn based Ukrainian is wired. Instead he fought on as a one armed fighter, throwing uppercuts and straight rights, and even switching southpaw in round 7 to be able to jab with his right jab. It was in the seventh where Derevyanchenko made his last significant stand, stunning Mbilli with a right hand briefly and opening up a combination in an attempt to press the advantage. After weathering the brief storm, Mbilli smiled at him and opened fire on his winded foe. By the end of the seventh, Mbilli had hurt Derevyanchenko badly, landing a right hand that had him wobbling back to the corner.

By the second half of the fight, it was Mbilli’s turn to experience the wear and tear that comes with prizefighting, revealing at the post-fight press conference that he injured his left shoulder early in the fight, limiting its effectiveness as a weapon. In the battle between one armed men, the younger, stronger fighter had the advantage. Mbilli never stopped searching for the knockout, battering Derevyanchenko until the final bell.

“He’s a warrior. He was in a difficult position, but he fought back,” said Mbilli, a 2016 French Olympian.

Derevyanchenko’s head trainer Andre Rozier defended his decision to allow the fight to continue, saying he was respecting his fighter’s wishes.

“I said, ‘Do you want me to stop this fight?’ and he said no. That is the sign of a warrior, and he continued to fight one of the best 168 pounders in the world with one hand,” said Rozier.

Derevyanchenko, who had pushed Danny Jacobs and Gennadiy Golovkin to the limits in world title fights, remained defiant in defeat.

“He’s a good boxer, a strong boxer,” Derevyanchenko said of Mbilli. “But if I had two hands, I think it would be another situation.”

Mbilli, who is co-promoted by Eye of the Tiger Management and Top Rank, is rated no. 1 by the WBC at 168 pounds and is a top three contender in the other three sanctioning bodies. He believes he’s done enough to distinguish himself as the best challenge remaining for unified super middleweight champion Saul “Canelo” Alvarez (61-2-2, 39 KOs), who is set to face Edgar Berlanga on September 14 in Las Vegas.

“Right now, I’m ready for big fights. I want to be world champion. I know, to be the best, I have to beat the best. I don’t want to say any names, but everybody knows who’s number one. I want the fight with number one,” said Mbilli.

“After [Canelo-Berlanga], I think I will be ready for him.”