There is no doubt that the best heavyweight fighter in the world is Oleksandr Usyk.

There is no doubt that the most significant fight in the heavyweight division will be the rematch between Usyk and Tyson Fury on December 21. A fight for three world titles, the title of lineal champion and recognition as the king of huge men.

This is the fight that matters most. That doesn’t mean other fights or fighters pale in comparison.

The Daniel Dubois vs. Anthony Joshua fight in London on Saturday is a huge event.

It is an significant fight, even though Dubois’ IBF title is secondary, rejected by Usyk because his contract required him to rematch Fury first.

It’s a huge fight, even though Dubois lost to Usyk and has two losses. It’s a huge fight, even though his opponents have five losses combined. Joshua has the other three of those blemishes – two of them at the hands of Usyk.

And yet it is a huge fight, not only because more than 90,000 spectators are expected at Wembley Stadium, but also because the match remains significant.

Their fight will establish the winner as the third best heavyweight in the world and set them up for a fight with at least one of the other two. And a huge part of what makes this so significant is those losses.

When people ask me why I prefer to write about boxing rather than baseball, my first love, I talk about how significant each fight is, how a boxing match is a chapter in history, not just a miniature piece of a puzzle spread out over the course of a season—a puzzle with a huge picture that hasn’t necessarily begun to take shape.

Like any other fight, Dubois-Joshua will tell the stories of two men entering the fight. It will tell the stories between the opening bell and the final bell, a mix of action and drama, twists and turns. And it will lead to recent chapters for the winner and the loser.

Both Dubois and Joshua were forced to rebuild – not once, but twice each.

First came Joshua’s initial rebuild. His jaw and defense were in question after his June 2019 loss to Andy Ruiz, when Joshua shockingly lost his three world titles on two major miscues. First, Joshua thought he was hurting Ruiz more than he actually was by knocking Ruiz down in the third round of their fight. Then, when Joshua came in for what he hoped would be the final blow, he did it from too close range and left himself too vulnerable to Ruiz’s counters. Ruiz went down once in the third round. Then Joshua went down twice.

Joshua had been hurt and knocked down two years earlier in his 2017 fight with Wladimir Klitschko, but Klitschko allowed Joshua to recover and come back for the win. There was no chance of that this time. Joshua was disoriented, the damage was ongoing, and it helped Ruiz finish him in the seventh round.

The fact that Joshua won the rematch six months later, regaining his titles in the process, was largely due to Ruiz coming into the fight significantly overweight, which made it easier for the wobbly Joshua to box cautiously from a distance, reminiscent of what Klitschko did when his jaw was shattered so long ago.

Klitschko eventually learned to emphasize his strengths and protect his weaknesses, which led to a long reign at the top of the heavyweight division. Joshua tried to rebuild and was able to score a knockout victory over Kubrat Pulev. But then came his defense against Usyk in September 2021.

The smaller Usyk was the better boxer, using feints and footwork – tricks and tactics Joshua hadn’t seen enough of and didn’t know how to deal with. By the end, Usyk had Joshua reeling in the final round.

That fight ended in a unanimous decision for Usyk. Their rematch in August 2022 ended in Usyk defending his titles by majority decision again. Joshua took the microphone and delivered a monologue that left viewers wondering if the former two-time heavyweight titleholder had not only lost, but had lost it – unable to cope with the reality of what had happened in that fight and what it meant for his future.

But over the past two years, Joshua has regained his confidence, admittedly against lower-level opponents – with a points win over Jermaine Franklin and knockouts over Robert Helenius, Otto Wallin and moonlighting mixed martial artist Francis Ngannou.

Is his confidence a facade? Is this renewed Anthony Joshua a mirage? His first really solid test will tell.

That test was Dubois. It was Joshua’s beard and defense that were questioned before, and rightly so. And it was Dubois’ heart that was criticized before. That criticism was highly unfair.

Dubois took a knee and counted to 10 in the 10th round of his November 2020 fight with Joe Joyce. He was ahead on two of the three judges’ scorecards. But he suffered a stern injury — a broken eye socket — and made a hard but strategic decision to protect his health and future.

The hearts of many fighters have been criticized over the years. And the best answer remains the example of beloved fighter Israel Vazquez, who ended his first war with Rafael Marquez with a broken nose, knowing that trying to beat his opponent was demanding enough when he was robust, but downright hazardous when he was broken.

Regardless of the reason for the loss, Dubois still had that mark on his record. So he worked through his mistakes in the gym, then tested himself against smaller opponents, picking up quick wins over Bogdan Dinu, Joe Cusumano and Trevor Bryan.

Then in December 2022 came the fight with Kevin Lerena, a smaller man who came up from the cruiserweight division and who perhaps gave Dubois more trouble than expected — but exactly what was needed.

Lerena had three knockdowns in the first round. In reality, Dubois had a leg injury and was having trouble literally dealing with Lerena’s powerful punches. But this time, Dubois felt it was an injury he could try to work through, especially considering what a second knockout loss would mean. Dubois won by technical knockout in the third round.

Now it’s time to fight for the title.

Dubois challenged Usyk in August 2023, losing by knockout in the ninth round but, in the eyes of some, winning a moral victory. That was because of what happened in the fifth round. Dubois threw a punch that, depending on your perspective, either went in the belt or came in low. The referee ruled it a low blow. Usyk went down on the mat. Some have incorrectly argued that Dubois was denied the knockout based on the time Usyk spent on his feet. But had the referee ruled it a legal punch, it’s entirely possible that Usyk would have gotten back up much quicker instead of spending some of his allotted time recovering.

Even with a moral victory, Dubois couldn’t afford to lose again in either of his next matches. While Dubois and Joshua’s most recent losses came to Usyk — who has proven to be one of the two best heavyweights in the world and is now the clear best — losses to other, lower-ranked opponents would potentially cost them a shot at making it out of the ring.

So it was a huge deal when Dubois defeated Jarrell Miller, stopping him in the final seconds of their December 2023 fight. And it was a huge deal when Dubois scored another technical knockout when Filip Hrgovic’s cut was ruled unfit to continue in the eighth round of their fight this past June.

Both Miller and Hrgovic were previously unbeaten. Losing to other contenders would have pushed Dubois to the sidelines, in danger of being relegated to the catchy-name measure. Instead, a win over Hrgovic established Dubois as a major contender and earned him the interim IBF title, reinforced by Usyk taking on Fury again.

Joshua, meanwhile, is proof that the sport can sometimes be what we as boxing fans want it to be – where fighters take on hazardous fights even if it means they might lose, and defeated fighters never give up hope.

We’ve seen too many boxers – or at least their managers and promoters – protect their records with a zero for fear that a loss would effectively end their ability to earn money. But the fact is Joshua remained a superstar in the UK.

Even the brightest stars eventually fade. Joshua wants to keep shining for as long as possible. He’ll have to outshine Dubois on Saturday. In the meantime, Dubois wants that torch to be passed. He’ll have to snuff out Joshua’s flame to make that happen.

Usyk-Fury is still the brightest star on the horizon. But Dubois-Joshua is going to featherlight up the night.