If you're joining us for the big one, then here's a little look at those unblemished records. Which one will fall tonight?

Image source, BBC Sport

Image source, Getty Images

Hall's corner tell him: "If you want to lose, carry on doing what you're doing."

Tough love from the trainers, but they're right - the challenger needs to work Haskins more if he is to take that IBF bantamweight belt.

Hall looks to have heeded that advice in the sixth though, he's landed more shots this round than previously in the fight but Haskins still won't be too worried at this stage.

Mike Costello
Radio 5 live boxing correspondent

The buzz around the fight is centred mainly on Golovkin and his first appearance in the UK. It's rare for a fighter of his status to appear here at his peak.

We are likely to see either another brilliant demonstration of clinical aggression from the hardest puncher in the history of the middleweight division. Or one of the great all-time upsets, to my mind the greatest produced by a British boxer.

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It's close heading into the fifth round as Haskins and Hall go for the IBF bantamweight title, but it's the man defending his belt who looks to have edged it so far.

Haskins is the more athletic fighter, and despite Hall's determination to get on the front foot it's the Bristol man who has landed the more eye-catching shots.

There's certainly no love lost between these two either, no touch of the gloves between rounds...

Watson: Heart says Brook R8. Head says Golovkin in 4 :( Good luck Brook.

Tom: Triple GGG rounds 6-8.

Chaney Riches: Ready for the boxing #bbcboxing, external would love to see a Kell Brook win but I'm going for @GGGBoxing, external 5th round knock out.

Not only is Brook out to take the world number one middleweight's WBC and IBF titles at London's O2 Arena, he is jumping two weights to do so.

Should he be successful, Brook would emulate the last reigning welterweight world champion to win a middleweight world title - Emile Griffith, in 1966.  

Brook is a world champion himself, of course, and an undefeated one at that, but the leap in weight divisions makes Golovkin the odds-on favourite in the bookies' eyes.

"This fight will separate me from the rest of Britain's world champions," Brook told BBC Sport.

Image source, Reuters

Remember this fella on the left?

Yes, it's Prince Naseem 'Naz' Hamed, multiple world boxing champion and pal of Kell Brook.

He's ringside to cheer on his Sheffield chum.

Image source, Getty Images

Image source, Reuters

Lee Haskins looks the more relaxed of the two British fighters, lowering his stance compared to Stuart Hall's close guard. But the Darlington boxer is the one who goes on the hunt early in the second round and almost catches Haskins with his left hand.

The Bristol puncher isn't fazed, though. His light footwork making him a difficult target for the veteran Hall and biding his time in a bid to pick his opponent off.

Kell Brook has been speaking since arriving at the O2 Arena tonight, he said: "I'm feeling very good. I'm all ready now, I just need to do the business tonight. 

"I've been relaxing, having a laugh and keeping as chilled as possible."

Tom Wells: GGG inside 6, Brook not adapted to middleweight just yet. Maybe after a tester against British standard fighter.

Kuda Godfrey: It's gonna be a tough night for Brook tonight but I've got faith that he can beat Golovkin on points!

Keep your chat coming. Hit us with your thoughts at #bbcboxing., external

Challenger Stuart Hall is first to make his way into the ring, shortly followed by the IBF bantamweight champion Lee Haskins - and it's the Bristol fighter's belt they're battling it out for tonight.

We'll be keeping you updated on this one, while continuing our build-up to Kell Brook's showdown with Gennady Golovkin.

Ben Dirs
BBC Sport at O2 Arena, London

Bristol's Haskins and Darlington's Hall have a bit of history - Hall, a former holder of the IBF bantamweight title, lost to Haskins when challenging for the European belt in 2012. 

Haskins is defending his world title for a second time, having been promoted from interim to full champion last November.

Lee Haskins may be the title holder, but Stuart Hall insists his opponent is "not world level" and didn't earn his belt - and the veteran Darlington boxer is out to prove just that.

At 36, Hall is in the twilight of his career but is a former champion himself, holding the belt in 2013 before defeats to Paul Butler and Randy Caballero.

This is surely his last chance to grab it back...

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Archie Artex: Brook will shock the boxing world, 6,7 or maybe 8

Alex Shcnopple: Brook of course, natural talent, unlike Man U losing to City & Millers giving away a 2 goal lead yet again. Great night ahead :D

Certified G: Golovkin in eight. Brook can take a battering, but he'll still fall.

Lee Haskins retained his IBF world bantamweight title in May with a unanimous points win over Mexico's Ivan Morales.

It was the Bristol fighter's first defence, having been awarded the belt out of the ring. Haskins was due to fight title-holder Randy Caballero last November, but the American was stripped of his crown after failing to make the weight.

"All I was thinking during the training for this fight was about Stuart Hall,"  he said at the time.

Well, Lee, now you've got him....

Image source, Getty Images

Ben Dirs
BBC Sport at London's O2 Arena

It has been a pretty low-key undercard so far at the O2 Arena in London, with a host of rather one-sided contests, a disappointing defeat for Charlie Edwards - who came a cropper challenging John Riel Casimero for the IBF flyweight title in only his ninth paid fight - before a pretty tedious victory for Liverpool's super-middleweight prospect Callum Smith. 

Smith, whose brother Liam defends his WBO light-middleweight title against Mexico's Saul Alvarez in Texas next Saturday, is biding his time before challenging the winner of a proposed unification fight between Sweden's WBC champion Badou Jack and Britain's IBF champion James DeGale.

Before we get to the big one tonight, there's the matter of another two British boxers fighting it out for a world title.

Darlington's Stuart Hall and Bristol's Lee Haskins go head to head - not for the first time in their careers and not even for the first time this week, with a few choice words and the odd limb thrown at their final press conference - for the IBF Bantamweight title.

It is a second defence of his belt for Haskins, who also beat his bitter rival back in 2012.

Golovkin the odds-on favourite

Brook the underdog

Is that how you see it going? Will GGG seal the deal early on? Or can Kell cause an upset?

Hit us with your big-fight predictions at #bbcboxing., external

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We've already seen Filipino Johnriel Casimero defend his IBF World Flyweight title by stopping Charlie Edwards, in only his ninth fight, in the 10th round this evening.

There was a comfortable sixth-round victory for Liverpool's Callum Smith against little-known Hungarian Norbert Nemesapati, while Martin J Ward won the British super-featherweight title when he halted Andy Townend in round eight.

Earlier on the undercard was Nigel Benn's son Conor, who stopped Joe Ducker with a ruthless display in the super lightweight division, taking his pro record to 4-0.

It took the 19-year-old only two rounds to see off the late stand-in boxer, having already knocked Ducker down twice at London's O2 Arena.