The stakes for Anthony Joshua and Daniel Dubois are titanic.

They fight for the IBF world heavyweight title in front of a full Wembley Stadium on Saturday night, live on Sky Sports Box Office.

For Dubois, victory would see him eclipse the man who has been the brightest star in British boxing for the last decade.

Dubois might have been elevated from Interim titlist to world champion without throwing a punch, but winning this would prove him worthy of the IBF championship he now holds but is yet to win in the ring or defend in the bout.

It would silence all the doubts that have been cast over him ever since the agonising knee he took to bow out against Joe Joyce. It would show Dubois could handle himself on the grandest stage of all.

For Joshua the implications are seismic. Winning the IBF belt would see him join a small, august group as a three-time heavyweight world champion.

His place in boxing history is being written. It will be assured if ultimately he fights for the undisputed title and all four of the major belts.

Beating Dubois at Wembley would, in all likelihood, lead to him to that epic end goal.

Tyson Fury is set to rematch Oleksandr Usyk for the other three titles on December 21.

The victors of these two fights are on course to box next year.

Joshua’s promoter, Eddie Hearn, said: “The one question I’ve been asked for the last 10 years is when AJ is going to fight Fury.

“If AJ were to win at Wembley and Fury was to turn over that defeat to Usyk in the rematch, you’ve got the biggest fight in the history of the entire sport in AJ vs Fury for the undisputed world heavyweight championship.

“For AJ, the dream has always been to become undisputed. Next Saturday, he has a chance to become a three-time world heavyweight champion and be one fight away from becoming undisputed, whether that is against Fury or Usyk.

“To see AJ-Fury for undisputed would be incredible,” he added.

“But the nature of the performances and results in the upcoming fights could lead us to the biggest fight of all time.”

But strip away all of that away, forget for a moment all that could lie ahead, the stakes and reward, and this fight is just that. A fight. An intensely personal duel between the two of them.

Joshua and Dubois knew each other years ago, sparred each other years ago, and it left them with questions both want to answer once and for all.

Joshua has looked to face down his opponent throughout the build-up to this fight. At 6ft 6in tall and over 252lbs (bigger than Dubois’ career heaviest of over 248lbs), Joshua is intimidating.

But he doesn’t believe Dubois is afraid of him. “I don’t think he’s scared of me. I think he might be nervous because he wants to perform, it’s a big occasion. There’s a big difference,” Joshua told Sky Sports.

The champion though is convinced that psychologically he has the edge in this fight. “Not because of that. I just think because I’ve been working on my mentality,” he said solemnly.

“I want to win.”

In boxing the metaphorical and the literal can blur. Joshua is prepared to take himself to dark places in a fight, to stretch himself to the limits so that when he meets the very best in the division, he’s not only able to compete with them, he’s able to beat them.

Dubois, once accused of being a ‘quitter’ himself, wants to push AJ beyond what he can take. For him the sweetest victory in the greatest fight of this life, wouldn’t be a knockout. It would be to subject Joshua to so much punishment that it makes the former champion quit.

“He has shown cracks,” Dubois told Sky Sports. “I know what I need to do. Break him down. Make him quit. Put that spirit on him and bring that out of him. Force that out of him and just go to war.

“I’m a younger fresher man. He looks good but he’s an old, worn-out fighter. He’s been in many battles. I need to just bring that out of him and make it a dogfight.”

That is for personal satisfaction. It would show that he was on Joshua’s level after all and deserving of all the respect that comes with that.

He’s sure that Joshua does not see him that way today. Dubois believes Joshua doesn’t truly register him as a threat. He reckons Joshua views him in much the same way as he always has.

“That little kid. Of course he does. They all see me as that little kid I used to see in the gym. That was quiet, that was sparring the GB squad, the GB days,” Dubois said, convinced Joshua is a making a mistake in that regard.

“We’re going to show him on the night. Just bring it on now.”

Dubois is a changed fighter. Since his defeat last year to Usyk, he has been regrouping. A win at a good level against Filip Hrgovic, saw Dubois pick the IBF Interim strap.

“I’m glad I still have a career,” he said. “I’m glad I’ve been able to come back. Because some fighters wouldn’t repair themselves.

“But I’ve come back and I’m going to show that I’m better and stronger and badder than before.”

Dubois has been working tremendously hard. He might be the champion, but he wants what Joshua now has – fame, acclaim and status, as well no doubt as the fortune that comes with all that.

Fascinatingly, for all Joshua now has in his possession, for all he’s achieved, he has an element of fear. Not of any particularly opponent but for himself, he fears sliding back.

“Do you know what my roadmap is? To get out of the struggle. That’s my roadmap. That’s why I fight. Because I don’t want to go back to being a young kid that’s getting in trouble. So that’s my roadmap, every opportunity they present me, whether it’s outside the ring, doing commercial work. Whether it’s in the ring, I’m going to do it,” Joshua said.

“Getting in the ring and fighting whoever they put in front of me, leads me to world championships, defences, Wembley stadiums, all that’s the glitz and glamour. But at the core of it, at the basis of it, I’m just scared to go back to where I came from.

“So I fight with my heart. And I’m very hungry to make sure I don’t go back there anymore.

“I need to stay out of the struggle. I need to. This is my way out. So whatever, let’s go. Whoever wants it can get it.”

In their different ways, they’re both trying to be what people said they wouldn’t, fighting to do what people said they couldn’t.

This title bout might well become the battle of wills Dubois wants it to be. One of them will endure that, one of them will break. Which, we’ll only find out on Saturday night, in 12 rounds. Or less.

Anthony Joshua’s heavyweight showdown with Daniel Dubois takes place on Saturday September 21 live on Sky Sports Box Office. Book Joshua vs Dubois now!