Keith “One Time Every Few Years” Thurman. Keith “Old Time” Thurman.

The former WBA/WBC welterweight champion has heard every insulting play on his nickname, “One Time,” during his often-frustrating, meandering journey toward this potentially redemptive moment Saturday night.

Thurman is convinced he’ll get the last laugh when he knocks out Sebastian Fundora for his WBC junior middleweight title. That he’ll face the favored Fundora at the same venue, MGM Grand Garden Arena, where he lost his WBA 147-pound crown to Manny Pacquiao nearly seven years ago is perfectly appropriate for a former champion confident he has at least one more elite-level performance left in his 37-year-old body.

“This is a beautiful moment, a beautiful opportunity, and we’re just looking forward to it,” Thurman told The Ring. “It’s gonna be a lotta fun. And to have that hand raised where my belt was taken, and now I have an opportunity to take the belt from a young champion, it’s just historic. This is what Hollywood boxing movies are about. They make movies about what is about to happen.”

The script suggests that Thurman is too small, too old and entirely too inactive to defeat Fundora — a 6-foot-6 southpaw who can thank him for the opportunity that got his career back on track in March 2024, almost exactly two years before their fight. It was Thurman’s biceps injury that afforded Fundora the chance to sub for him against Australia’s Tim Tszyu, then the unbeaten WBO junior middleweight champ.

Fundora upset Tszyu by split decision in an unforgettable bloodbath to win the WBC and WBO belts. He was later stripped of the latter, but he is 3-0 since Brian Mendoza tattooed him with three punches that knocked Fundora flat on his back and out in the seventh round of their April 2023 bout in Carson, California.

Fundora (23-1-1, 15 KOs) has been a different fighter since Mendoza defeated him. He has used his jab and distance more effectively and has become harder to hit.

Thurman still sees vulnerability in an aggressive volume puncher who stands almost a foot taller than him and is nine years younger. He taunted Fundora on Thursday, when during their final press conference he promised to apply the strategic tips Mendoza gave him as they sat next to each other on stage.

“A lot of people hit him,” Thurman said. “Mendoza hit him in a major fashion and finished him. [Erickson] Lubin hit him and dropped him, but he was able to get out of it, survive and become the dominant force once again in that fight. So overall, I just see that he can be hit. I think Tim Tszyu was hitting him before they decided to stop the fight. I look at the offense and I look at the defense, and his offense is superior to his defense.”

Tszyu hasn’t been the same since his damaging first fight with Fundora, which was one of the reasons his handlers halted his rematch with him following the seventh round July 19.

Thurman, however, is preserved physically. He never mentioned retirement, yet injuries, the COVID-19 pandemic and other factors have limited the Clearwater, Florida, native to just two fights since Pacquiao beat him by split decision in July 2019.

Thurman (31-1, 23 KOs) hasn’t fought a championship-caliber opponent since he beat Mario Barrios in convincing fashion four years ago. He nevertheless believes he has the athleticism, power, ring IQ and skill to set traps and knock out The Ring’s No. 2 junior middleweight in their Premier Boxing Champions pay-per-view main event (8 p.m. ET; $74.99).

If that transpires, Thurman will happily accept another altered nickname, Keith “One More Time” Thurman.

■ Moses Itauma (13-0, 11 KOs) needs rounds, but the 21-year-old rising star shouldn’t settle for going the distance with Jermaine Franklin on Saturday night. If Itauma truly wants to make a statement in their 10-round fight at Co-op Live Arena in Manchester, England, he needs to become the first fighter to knock out the durable American contender. That would amount to a persuasive performance across the pond, where two other hard-hitting Brits, Dillian Whyte and Anthony Joshua, went 12 rounds in back-to-back bouts with Franklin (24-2, 15 KOs) in November 2022 and April 2023.

■ Fundora’s remarkable ability to make the junior middleweight limit with relative ease isn’t simply the byproduct of an accommodating metabolism. His professionalism is also a significant factor in someone so unusually tall for the division regularly stepping on the scale at less than 154 pounds. The Coachella, California native has weighed 153½ pounds or less for each of his past 15 fights. Fundora, 28, has weighed below 153 pounds for each of his past three fights, evidence that he can continue fighting at junior middleweight for the foreseeable future.

■ Elijah Garcia (17-1, 13 KOs) is in dire need of an impressive victory when he encounters Kevin Newman III (18-3-1, 11 KOs) on the Fundora-Thurman undercard. Garcia is still only 22, but the southpaw lost all of his when the middleweight’s 2023 consisted of knocking out previously unbeaten Amilcar Vidal in the fourth round, outpointing Kevin Salgado unanimously in a 10-rounder and stopping eventual WBA super middleweight champ Armando Resendiz in the eighth round. The Wittmann, Arizona, native has fought just twice since he defeated Resendiz and not since his debatable split-decision defeat of Terrell Gausha a year ago.

■ Xander Zayas might not be the opponent boxing fans want Jaron Ennis to fight next, but the smoke-seeking WBA/WBO 154-pound champion deserves a lot of credit for embracing a dangerous assignment most junior middleweights would just as soon avoid. Zayas (23-0, 13 KOs) will be a sizeable underdog against Ennis (35-0, 31 KOs) if their fight is finalized, but boxing Abass Baraou after he'd upset Yoenis Tellez and Ennis in the first half of 2026 speaks to the developing Puerto Rican champion’s commitment to challenging himself.