If Keith Thurman is going to pull off the upset against Sebastian Fundora, it’ll likely take that level of performance.

Thurman will attempt to become a two-division champion on Saturday with the WBC 154-pound title on the line at MGM Grand Garden Arena in Las Vegas on Prime Video PPV.

Fundora (23-1-1, 15 KOs) and Thurman (31-1, 23 KOs) were originally scheduled to fight Oct. 25, but a hand injury forced the former to withdraw and the rest of the card was postponed. Fundora is a heavy betting favorite at minus-380 by DraftKings Sportsbook, while Thurman is a plus-280 underdog.

Thurman, a former unified welterweight champion, is coming off another lengthy layoff. He ended a three-year layoff March 12 last year and beat an overmatched Brock Jarvis by third-round TKO in Australia. The 37-year-old has only fought four times since 2018.

Fundora, nine years his junior, last fought on July 19 and delivered a more definitive victory over Tim Tszyu in their rematch, stopping the former WBO champion after seven rounds.

“The Towering Inferno,” who stands at 6-foot-5 1/2 and will have a seven-inch height advantage over Thurman, beat Tszyu by split decision in March 2024 to unify the WBC and WBO titles in one of the bloodiest fights you'll ever see after an inadvertent elbow cut the Australian along his hairline late in the second round.

Fundora had replaced Thurman, who withdrew with a biceps injury, to face Tszyu first time around. Now, after there had been two degrees of separation between them, their paths will cross. Here's what it will take for Thurman to climb the proverbial and literal mountain that he's facing.

Fundora, who is a southpaw, is at his best when he gets his opponent to stay in front of him at the end of his reach and unload a barrage of punches.

Thurman must avoid these situations at all costs. If he’s standing in front of Fundora and can’t get inside his 80-inch reach, he’ll likely struggle to find any success. Fundora boasts an 11-inch reach advantage over Thurman.

Fortunately for Thurman, Fundora hasn’t fought someone with his boxing ability. At his best, Thurman does a good job of moving and being the aggressor.

In this case, using angles and keeping Fundora from setting his feet to let his hands go will be vital to pulling off the upset. In particular, if Thurman can keep moving to his left, he can keep Fundora chasing him and make it difficult for him to sustain any offense.

Thurman’s experience and boxing acumen will have to play an important role if he’s going to emerge victorious. And if Thurman can use that along with his footwork to limit the output and damage Fundora can dish out, his chances of pulling off the upset rise exponentially.

If Thurman is going to keep Fundora from planting his feet and letting his hands go, he’ll need to land his jab and left hook consistently. Thurman could use both punches to counter and take away Fundora’s jab, which can make him much more predictable and make it easier to manage distance.

The right hand is normally the weapon an orthodox fighter finds success with against a southpaw. While Thurman shouldn’t stray away from that punch, he has to be careful throwing his right hand too much.

Thurman has been hurt to the body multiple times, and two such occasions came against southpaws, Luis Collazo and Manny Pacquiao. Pacquiao’s shot to the liver changed the tenor of the fight by halting a late rally by the then-WBA welterweight champion. Pacquiao won by split decision, giving Thurman his lone defeat in July 2019.

Establishing the left hand won’t just help negate Fundora’s lead hand; it could keep him out of bad spots defensively. It can also help him walk Fundora into traps and counter shots, both making his path to a win more feasible.

One of the best ways to slow down someone is to catch him early and make him wary of return fire.

It’ll be especially important for Thurman to do that. Even at his peak, we’ve seen Thurman have lapses in the middle or late rounds, and one figures that won’t get better with the time that has elapsed.

If Thurman can land a big shot early that makes Fundora respect his power, it could slow the pace. A slower-paced fight greatly favors Thurman, whereas Fundora would prefer to have a high punch output and force the Clearwater, Florida, native to fight him off.

And if Thurman can connect with enough significant shots that allow him to be on the front foot and push Fundora back, he’ll be well-positioned to chop him down.