Four bodies crowd around Jo Jo Dan in his corner. What are they supposed to say?

A right upper cut did for him first and hang on a minute... FIGHT OVER. He will not come back for a fifth round.

Right, left, right from Brook after 60 seconds of reprieve. It gets him in close, another three-shot combo. Short, sharp shots.

Dan started this fight with a confident bounce but my word he has had it drained away from him and he is down again.

It's a standing eight count for the IBF's number-one rank. Here comes the bell... no... a fourth knockdown.

Earlier tonight, it was complete domination for Frankie Gavin in his welterweight bout against durable but limited opponent Bogdan Mitic from Serbia.

Gavin, a Commonwealth Games gold medallist in 2006, won all 10 rounds to seal a 100-90 points win and will fight again in May against South African Chris van Heerden for the IBF international welterweight title.

Image source, Matchroom Sport

Mitic only landed 12 punches but Gavin, with 22 wins in 23 professional fights, admitted he needed to raise his game.

He said: "I didn't get out of my comfort zone. I won every round easy enough, but I really should have taken him out of there. I will have to be better than that and I will be. I was trying too hard."

Tony Bellew
Former light heavyweight world title challenger on Radio 5 live

"It was another big round for Kell and he can sense Jo Jo Dan is on the edge. Jo Jo Dan has already tried to punch low a couple of times. He is getting smothered and I feel that Kell can land that one big punch to finish it."

Click on the live coverage tab to hear BBC Radio 5 live commentary.

"Everything is perfect" says Kell Brook's man in the corner Dominic Ingle.

A stoppage here would send a message. Dan is no mug.

Kell Brook has his trigonometry down to a tee. His angles and distance are on point. He bounces into range and throws a left upper-cut which misses but comes back, left jab lands, Dan takes it.

Where is the Brook right hand? It must be itching to let fly? One, two, three - he leaves it until last but narrowly misses with a cross-shot.

Dan engages in a grapple but gets pushed about. There is nothing down for him here. Bell. The challenger looks demoralised to say the least. What answers have you got Jo Jo?

Tony Bellew
Former light heavyweight world title challenger on Radio 5 live

"Jo Jo Dan took everything in that round. Kell has the measure of him. Jo Jo Dan is known for being tough and having a great chin, but when you become a world champion you find a new level. And Kell is proving that. He is better than Dan has ever seen before."

The only option Jo Jo Dan has is to grapple. Tie up the champion. He looks like a rugby player at one point, almost hugging Brook around the waist.

The right hand is the money maker for Brook. It's causing damage like a wrecking ball. Even as the bell goes Dan does not want to let go.

At one point Dan looked like a giraffe on ice. His legs were gone. He needs the stool and may well need it again soon.

No doubt Brook bettered those early exchanges. He was selective with his punches just like when he claimed Shawn Porter for the IBF title. Punch when it's worth it.

Right hand upper-cut and BANG... Jo Jo Dan is down.

Dan is floored again. He is all over the place here. Another right hand put him on the deck for a second time in a matter of seconds.

Tony Bellew
Former light heavyweight world title challenger on Radio 5 live

"He is landing the right hand with ease and it was a good first round from Kell. I'm going out on a limb and say Kell will be the first man to stop Jo Jo Dan."

Brook lands a right to the face and draws a welcome roar from the crowd. Some naughty stuff from Dan as he wants to put the digs in when the pair grapple. He has a few slappy punches when they lock together and looks to graze his head across the champion's.

Jo Jo Dan is all in blue, Brook in red.

The Romanian is bouncing, energetic, he looks game and comes forward but Brook catches him nicely with the left hand, a counter punch. No sign of anything new from Brook after his leg injury and rehabilitation. He looks poised. Tight hands close to his chest.

The fighters meet in the centre of the ring and walk back to their corner, a huge roar goes up, we are off...

"Yorkshire, Yorkshire," shout the masses.

Kell Brook was giving away a fraction in weight when the fighters weighed in on Friday but both will have inevitably piled the food into them after cutting down for the scales.

Brook came in at 10st 5lbs 9oz, with Dan 10st 6lbs 4oz.

Image source, Getty Images

The champion also gives away a little in reach, so will have to move well if he is to avoid being jabbed all night long.

Here we go, it's Michael Buffer time: "The officials are ready, the fighters are in the ring and are ready, boxing fans are you ready?

"Sheffield England, are... you... ready?

"For the thousands in attendance and the millions watching around the world, ladies and gentlemen, let's get ready to rummbblllee."

"Ladies and gentlemen please remain standing for the national anthem of the United Kingdom," announces Michael Buffer.

Brook puts one glove on his chest and the Sheffield crowd let rip.

"This is the main event of the evening. Twelve rounds of boxing for the IBF championship of the worrrrlllddd," continues Buffer.

Tony Bellew
Former light heavyweight world title challenger on Radio 5 live

"If Kell shines tonight it will be a big statement and if he does a job on Jo Jo Dan it's big news for America. It might not get him a shot at Floyd Mayweather or Manny Pacquiao, but it will get him Amir Khan as he will be a name in America.

"If he beats Khan then he will be able to look at getting a shot at Mayweather or Pacquiao.

"Amir Khan is the darling of the media in the UK and has been a for a long time, but Kell is very well liked in the media and by the fans. There are 10,000 people here and no one is here for Jo Jo Dan. A fight between Kell and Amir is a huge fight for Britain."

Listen to live commentary from BBC Radio 5 live by hitting the live coverage tab.

Image source, Getty Images

Boxing's stepping-stones have conspired to create a path from Amir Khan to Kell Brook but the pair will not meet in the middle to get it on, according to Brook's promoter Eddie Hearn.

"Amir Khan has said 'go and fight someone good, go and win a world title'," Hearn told BBC Radio 5 live. "Well do you know what, we went and fought someone good and went and won a world title and now we sit with Amir Khan this summer with no opponent.

"We sit there with a date at Wembley of June 13th where Amir Khan could fight Kell Brook in another 80,000 blockbuster and Amir Khan doesn't want to know.

"The bottom line is, Amir Khan knows that Kell Brook beats him. Why wouldn't you take Kell Brook when he is the biggest payday out there for you and he has a world title? it just doesn't make sense."

Tony Bellew
Former light heavyweight world title challenger on Radio 5 live

"The atmosphere here is outstanding. There's no better feeling than walking into a reception like this.

"Kell looks fantastic and I think we will see the best of him tonight. You would never believe he has been out of the ring for so long."

Kell Brook is in the ring. He skips as he enters. Surely he will leave the ring with the belt again.

You know it's a big fight when delegates flood the canvas before the off. There are loads in there, all looking important but the thousands in attendance only care for one man.

Still Brook's entrance song plays and he stares across the ring with his belt hoisted behind his head by Lee Noble.

National anthem time.