Charles: Can't believe this fight happening in front of just 12,500 people, almost all of whom will have been corporate 'freebies.' I know it's just the undercard but it's more like watching the snooker than a heavyweight title fight.

Lewis: It is rubbish how alienating the modern PPV is becoming. £25 for a fight stream is a bit steep. Its a shame. It makes it far more difficult to keep up with careers. UFC know the importance of accessibility to client base, and the WWE found a much better balance.

Heavyweight Derek Chisora: "AJ better win. The whole nation is counting on him. We need him to win. You don't get it. We need him to win. If he don't win it means your paycheque goes down."

Middleweight Hamzah Sheeraz: "I hope and pray AJ does it because I'm a massive fan of the way he goes about it. But if you're talking from a boxing perspective, I do think Usyk is going to get the better of him again. But my support is with Joshua all the way."

Four-time world champion Carl Froch: "My prediction to be honest is a prediction that I don't even want to hear. I think Usyk beats AJ quite conclusively again - maybe even gets the stoppage."

Super-bantamweight Ramla Ali: "AJ will win this one. Like when he lost to Andy Ruiz, he made some changes, and I feel like he's doing the same again - he's making changes."

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

I can’t recall any other British fighter being subjected to the level of scrutiny that Anthony Joshua is put under.

What’s his body language like? Does he look nervous? Why did he shake Usyk’s hand? Does he have the desire? Has he lost the mind games?

Throughout fight week, we’ve all speculated on his psychological state and how that first win – a convincing one for Usyk – has impacted Joshua. Reporters, ex-fighters, fans; we’re all guilty of it.

Personally, what I have seen from him this is week is a man who is fed up of all the questions.

In an interview yesterday, Joshua said that he doesn’t say too much because his words are always picked apart.

All he wants to do today is fight. To right a wrong on his record.

Image source, BBC Sport

The main event comes after the current heavyweight bout between Zhilei Zhang of China and Filip Hrgovic of Croatia.

Hrgovic had to take a count early on after his gloves touched down and a horrendous clash of heads then left him with blood streaming down his face.

But we're still going on in the fourth with Usyk and Joshua waiting backstage.

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

We're officially into Sunday here in Jeddah. We could be nearing 01:00 local time by the time the first bell of the main event rings.

Image source, Mark Robinson

Veteran Chinese heavyweight Zhilei Zhang is sporting this tremendous outfit for his undercard bout with Filip Hrgovic of Croatia.

Over in the United States, Deontay Wilder looks on enviously.

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

This whole event is up against a backdrop of controversy surrounding Saudi Arabia hosting high-profile sports events.

Campaigners such as Amnesty have accused Saudi of ‘sports washing’ its reputation in other parts of the world, highlighting the country’s human rights record and military activities in neighbouring Yemen.

Joshua has said he is just here "for boxing". Matchroom promoter Eddie Hearn said he has seen changes in Saudi over the past few years and cited an increase in boxing participation in the region, whereas Amnesty told us the situation in Saudi is getting “much, much worse”.

Over the past week, the promoters and boxers involved have repeatedly thanked Saudi Arabia officials for hosting the fight.

I don't think this is the last time we'll see a world-level boxing hosted in the region.

READ MORE: Sportwashing fears persist in Saudi Arabia

Lightweight Adam Azim: "I'm going with AJ this time. I think he's more determined. He's training hard. It could be like [Andy] Ruiz II, but I think this time he has to push it on him rather than box him."

Super-welterweight Liam Smith: "It's a tough one but you have to edge towards Usyk. If Joshua puts it right on Usyk, I think he can win. Joshua has fought in Saudi before but I don't think the location makes a difference. The winner has to go on to fight Fury."

Boxing coach Dave Coldwell: "It's a huge ask for AJ but he has the physical attributes to turn it around. The problem is that Usyk has skills to negate that. AJ will always have the power and pop in his hand to end the fight, but he has to get off to a really quick start and stop Usyk from getting into a rhythm. If Usyk does get comfortable, he will be unshakable. I would say Usyk is the favourite but AJ is a live underdog.

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

With all the fight week engagements, it’s been a hectic six days here in Jeddah.

Overlooking my hotel is the Jeddah Corniche Circuit, where the Saudi Formula 1 grand prix is held. I say street circuit, most of it is closed off to the public.

Image source, BBC Sport

In general, this side of Jeddah – adjoining the Red Sea - is disconnected from what many would consider ‘real life’. There is a mall nearby with high-end luxury shops, but there is not much to do or see.

On Thursday, with a few hours of downtime, I was able to take a bus ride and explore the other side of Jeddah with a visit to the historic town of Al Badad, an UNESCO heritage site.

Image source, BBC Sport

Image source, BBC Sport

It is the oldest town in Saudi; crumbling buildings with stray cats wandering the soot-covered streets. But the town was also full of life and vibrancy; food carts, locally owned shops selling textiles and jewellery and Jeddah’s oldest mosque.

Image source, BBC Sport

Wombat: Hopefully Fury's wrestling training has taught him a thing or two. Make a surprise ring wall, distract the referee, take out Usyk behind his back, let Joshua stand tall and stare each other down with all the belts raised high. The main event we all need.

Jay: First fight was a lot closer than most people think. The belts are coming back to Britain tonight.

Promoter Eddie Hearn, Matchroom Sport chairman, said: “This is the unified world heavyweight title between two greats of boxing. It doesn’t get any bigger than that.

"Oleksandr Usyk; an Olympic gold medallist, the pound-for-pound number one, former undisputed cruiserweight and current unified heavyweight champion.

“Anthony Joshua; also, an Olympic gold medallist, became heavyweight champion in his 16th fight, unified the division in front of 90,000 people in his 19th fight, and has changed the face of the sport around the world.

"Two tremendous fighters, two tremendous athletes, champions, and ambassadors of the sport that people in Saudi Arabia and all around the world can be inspired by. It’s been an incredible week and the best is still to come.”

By the end of tonight, Anthony Joshua will either be a three-time world champion or will have suffered his third professional loss.

Where does he go after tonight? Our experts have discussed what will happen next for AJ if he was to win or lose.

Here's the champion backstage getting prepared....

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

This fight means so much more to Oleksandr Usyk than defending his world titles and unbeaten record. He’s carrying the hopes of a nation.

He’s had some journey over the past 11 months. You can only imagine the toll it has taken on Usyk, both physically and mentally. By his own admission, he needed the help of a sports psychologist when he returned to training.

But what I’ve seen this week is a man who has channelled the spirit of his country into positivity. From performing coin tricks at the public workout to singing Ukrainian folk song at the weigh-in, Usyk has been on form.

Oleksandr Usyk is widely considered one of the pound-for-pound stars of boxing - if not the leading star. But his preparations have been far from straightforward.

Just five months after beating Anthony Joshua at the Tottenham Hotspur Stadium in September, he was defending his country against the Russian invasion.

He left Ukraine in March to begin a training camp in nearby Poland. At the back end of his camp, he had been training in Dubai.

To complement his outfit, Usyk was sporting a fully shaved head with a single lock of hair, a traditional Cossack haircut, known as oseledets.

"We were born to compete for life, for belts, for anything," he said. "The one who does not compete does not live. All our lives are competition, for anything, something, for somebody. That's why we're competing."

Oleksandr Usyk said: "It is very important for me, my team, my country, and I’m really happy to be here. It's not my first time, it's my third time in Saudi Arabia. I feel like I'm going to be here again and again.

“We learned from each other in the first fight, but this is a continuation and the first round on Saturday will be round 13. We had enough time to study each other. We were born to compete for life, for belts, for everything. The one who does not compete, does not win.

"All our lives are competitions for something or somebody. That’s why we are competing. We’ve had enough time to study each other and this will be a great, great fight.”

More predictions...

Matchroom promoter Eddie Hearn: "I want to see a dominant performance from Anthony Joshua - I feel like he's the best heavyweight in the world. I want to see him break down and fundamentally beat up the pound-for-pound number one."

Former British super-middleweight champion Paul Smith: "If I had to put my house on someone I think the safe bet would be Usyk. But I'm hoping Anthony Joshua will pull it out and stop him mid to late rounds."

Boxing trainer Ronnie Shields: "AJ is good in second fights. I don't think he's going to knock him out, But I think he's going to win a decision."

Former European super-bantamweight champion Spencer Oliver: "I think Joshua is going to get the job done inside six, seven rounds. I think he's going to catch Usyk."

Dave Beaumont: All the predictions for Joshua are based purely on hope. Hoping he can catch Usyk, hoping something different can happen. The fact is, we've seen the fight once, Usyk is simply streets ahead. He will win easily again.

Kal Sajad
BBC Sport at King Abdullah Sports City Arena, Jeddah

Joshua has (sort of) been here and done it before. In December 2019, six months after his shock loss to Andy Ruiz Jr, the Briton recaptured his heavyweight titles with a dominant points win over the Mexican.

That rematch took place in Riyadh, the capital city of Saudi Arabia. While a lot can be taken from that experience, there are certain caveats.

A complacent Ruiz Jr was ill-prepared and out of shape for the second fight. And Usyk is not Ruiz Jr – he is a boxing technician, a pound-for-pound star.

I have spoken to ex-fighters, pundits and media throughout fight week. Away from Team Joshua, I haven’t found many people who are tipping AJ to regain the world titles.

READ MORE: How will AJ approach the rematch?

Steve Bunce
Boxing expert on BBC Radio 5 Live

I'm struggling to find a case in British fighting history where a British fighter has been placed under so much pressure, including being named as the massive underdog.

I don’t think it’s ever happened, I really don’t.