LAS VEGAS (AP) — Keith Thurman certainly seems like more than the modern Manny Pacquiao should be able to handle.

Thurman (29–0, 22 KOs) is a decade younger, certainly more powerful and maybe even a bit faster than his famously speedy opponent. Thurman is a tough, voluble welterweight champion in his prime competitive years, and Pacquiao represents the biggest fight of his career — a once–in–a–lifetime chance to pound a boxing great into retirement.

“It’s been a build up and a progression my whole career toward this moment on Saturday night,” Thurman said. “This really is the outcome of an individual living out their dream.”

So why are the 40–year–old Pacquiao (61–7–2, 39 KOs) and trainer Freddie Roach so confident heading into the MGM Grand Garden in Las Vegas? And why is the older eight–division champion actually a slight betting favorite against one of the best 147–pounders in the world?

After 18 years together, Pacquiao and Roach believe Thurman is just another challenge to be overcome by hard work, smart planning and the psychological edge of experience.

Thurman looks daunting on paper, but Pacquiao and Roach are virtuosos on canvas.

“Tomorrow night, class is in session,” Pacquiao said Friday after the weigh–in. “I hope Keith Thurman studied hard, because Professor Pacquiao gives very hard tests.”

Pacquiao and Thurman both hold versions of the WBA 147–pound title heading into this Fox Sports pay–per–view showdown. In Roach’s educated mind, the vaunted Thurman has far more questions to answer than Pacquiao, who is coming into this fight off back–to–back victories over Lucas Matthysse and Adrien Broner.

Can Thurman recapture his prime fighting form after two years of relative inactivity caused by a 22–month injury layoff? Can he match Pacquiao’s legendary speed while showing the stamina to fight effectively for 12 rounds against Manny’s famed pace?

“I hope Thurman brings his best, because that’s when Manny will be at his best,” Roach said. “Thurman is a good fighter, but Manny beats good fighters all the time. And I don’t think Keith Thurman is a great fighter. I think Broner is a better fighter, and Manny took care of him (easily).”

While Thurman is in the biggest bout of his career, the Filipino senator’s late–career resurgence also reaches a vital point Saturday. Despite what Roach says, Thurman seems certain to be a big step up in competition from Matthysse and Broner, and the cumulative effects of a boxing career rarely wear well after 40.

“Manny isn’t going to do anything with those little T–Rex arms,” Thurman said. “He’s about to get beat up. I get to punch a senator in the face, and he’s going to feel it.”

Thurman earned the nickname “One Time” with his one–punch knockout power, yet he has stopped just one of his seven opponents since December 2013. And though Thurman is still in his ostensible prime, he has shown a few signs of weariness with his sport.

He has never looked more vulnerable as a professional than he did in his comeback victory last January over tough veteran Josesito Lopez, who rocked Thurman repeatedly and even won a 10–8 round without a knockdown. More recently, Thurman has repeatedly spoken about how he’s eager to get a few big paydays and then get out of boxing — a sensible mentality that nonetheless could indicate a fighter’s focus isn’t completely on competition anymore.

Thurman has been totally focused in public appearances for this big–money bout, however.

“I’m going to do to Manny Pacquiao what he did to Oscar De La Hoya,” Thurman said, referring to Pacquiao’s landmark victory over the Golden Boy in 2008.

While Thurman would love to retire his opponent, Pacquiao plans to keep competing indefinitely, and he doesn’t dismiss the notion of fighting to 50 and beyond, as Bernard Hopkins did. He has openly looked beyond Thurman to his hopes of a second fight with the retired Floyd Mayweather, or a unification bout with champion Errol Spence.

But just in case anybody believes he isn’t focused on Thurman, Pacquiao said that even his mother took offense at Thurman’s pre–fight trash talk , including his vow to “crucify” the vocally evangelical Pacquiao.

“I’m just always smiling, no matter what Keith says,”Pacquiao said. “It’s easy to say things, but it’s not easy to do it in the ring. I’ve been in this sport longer than Keith Thurman, so my experience will be the difference.”