Tyson Fury has the chance to claim revenge and the WBO, WBC and WBA heavyweight titles when he takes on Oleksandr Usyk on Saturday in Saudi Arabia.
Usyk beat Fury on points to become the undisputed champion in May, the first in the four-belt era, but has dropped the IBF belt for the rematch.
Fury, 36, is facing the only man to inflict defeat on him in the professional ranks.
The Briton is a slight underdog as he aims to become the first fighter to beat 37-year-old Usyk.
You can follow live text and radio commentary from 20:00 GMT on Saturday on BBC Sounds, BBC Sport website and app.
Will Fury become a three-time heavyweight world champion or will Usyk's undefeated streak continue?
BBC Sport has asked the world of boxing for their predictions.
Usyk v Fury
Saturday, 21 December - programme starts at 21:00 GMT
British heavyweight champion Fabio Wardley: "As a boxer and as a person, Fury is capable of making the adjustments to beat Usyk but do I think he will actually be able to and whether the ambition is still there? Without being offensive, it may be lacking a little. With Usyk, he is so stoic and stalwart and 100% focused on getting the job done. I think it will be a hard task to rip the belts away from him."
Former undisputed heavyweight world champion Lennox Lewis: "Tyson Fury wins this because he is the bigger man. He will use his jab and needs to throw more punches than the first fight. He can't muck around and needs to be totally serious. I always say the bigger man always wins if they have the same skills."
Welterweight world champion Natasha Jonas: "I think Fury will be more on it and he can do it this time."
Heavyweight Lawrence Okolie: "I will back Fury, which sounds insane because we've seen Usyk do it countless times and has even beat Fury already. It was such a close fight and Fury still has another style to try. He has an opportunity to not try and outbox the boxer as he did and try to be more aggressive. He can be a big strong guy and back it up with boxing skill. At times when he was stepping off, maybe he'll now step forward. Maybe it makes it more ugly, messy and gritty. What I will say is that one of them will win more convincingly than last time and that could also be Usyk if he stays consistent like his last fight. If he's in even better shape than Fury, he could win by a bigger margin than last time."
Heavyweight Frazer Clarke: "Fury can make amends and you can never doubt him, but I do think Usyk will win."
Light-welterweight Jack Catterall: "We’ve seen a lot of good early rounds from Fury, so it’ll be interesting to see if he has made adjustments and whether they can be enough against Usyk, who can adapt to anything. As a British fighter I want Fury to win, but my head says it won’t be enough against a fighter like Usyk."
American fighter Regis Prograis: "I picked Fury the first time, I’ll pick Fury again. Usyk is a beast, you can put him up there as one of the best ever, he’s hot, he has beaten everyone – AJ twice, Fury, Danny Dubois. But I have got to go with the big man."
Former world champion Sunny Edwards: "The first fight was competitive but I think Usyk won conclusively enough. At any time it is very hard to pick against Usyk, even if you are as big and as good as Fury. Usyk gets in the ring and is on a different rhythm, he's on a different engine. Usyk just seems to have this momentum and he's always making his opponent work a lot harder. I have to go with Usyk but you can't write Fury off. When you write Fury off that's when he does something he isn't supposed to."
Matchroom promoter Eddie Hearn: "I have a lot of history with Usyk but I'm backing Tyson."
British flyweight Galal Yafai: "I'm going Usyk again. I like Fury and I like Usyk, but there's one thing me and Usyk have in common, we are both Olympic champions, everything else I don't come close to him."
Super-flyweight prospect Shannon Ryan: "It will be the same result, Usyk by points. I think it will be competitive and Fury will bring more and be more switched on but Usyk will take over from round eight onwards.”
Scotland's first female world champion Hannah Rankin: "I’ve been tearing my hair over this one, it’s taken me so long to come to a decision. It may be a little bit controversial but I will go with Fury. I think the loss has really got to him. He’s training really hard and has the bit between his teeth. Normally rematches go the same way but I will go with Fury on points. He will learn from his mistakes and be super focused.”
Heavyweight prospect Moses Itauma: "Fury can win but it's whether he makes the necessary adjustments. I haven't seen Usyk's camp though, I need to see both camps."
Retired world champion Richie Woodhall: "It has to be a disciplined display but I think Fury will do it. Most people are saying Usyk again and he might raise his game but Fury has the physical advantage. As long as he's had a good camp and he comes in as fit as he can be. I think this could be the best we see of Fury."
South African heavyweight Kevin Lerena: "I believe Tyson will knock him out. We know Tyson can box. He was boxing his ears off and having a great time before he got caught and the fight swung in Usyk's favour. Take away those rounds where he had to recover, Tyson would have won."
Boxing coach Dave Coldwell: "I wouldn't say it's a 50-50 fight, but I would lean to Usyk on a 55-45. If Usyk still has enough in the tank, he beats him again. He's very good at riding out little crisis moments and he's always done it throughout his career. He's been hurt several times but rides out the rocky moments. He will probably get hurt again in this fight, but he doesn't panic and knows how to handle adversity."
Heavyweight David Allen: "I thought Tyson would win the first fight and that he would stop him. Usyk forced the pace, he made him work. A lot of people say that Tyson dropped the ball. I think Tyson wins the rematch. I don't think there's a heavyweight out there that beats him. You just don't know when you're over the cliff. You can spar all you want, but you just never know. I would go for Tyson to win because he has a touch of genius but you can say that about Usyk."