Spence throws a left to the body that would have caused some damage, but Brook sees it coming and can just get his guard there in time.

Overall though in the first three minutes it is a solid, if slightly cagey, start for the current champion, with the American having little to celebrate.

A powerful left cross and it is immediately followed by a tasty right. It is a solid start for the Englishman.

And here we go...

Adam Booth
Former trainer of David Haye on BBC Radio 5 live

The atmosphere inside here is sensational. Kell's face looks tense while Errol looks a bit more relaxed.

Wayne Ellis - Khan vs Brook hasn't happened yet because Khan has constantly ducked him...

"For the thousands in attendance and millions watching, wishing they were in attendance, from Sheffield, England, let's get ready to rumble."

It doesn't sound much written down. OK, let's do it justice, it was more like "let's get ready to rrrrruuuuuuummmmbbbbllllleeeee."

As always, Michael Buffer's magic words drive the fans crazy. And the atmosphere sizzles even more.

We have had the national anthems and we are nearly ready. This is Kell Brook's chance to not only retain his world title, but become a huge name to an American audience.

Also, any hope of a fight with Amir Khan surely needs the Englishman's arm to be raised later on.

Howard Foster is our referee tonight.

Image source, Rex Features

Anthony Crolla, the former WBA lightweight world champion, knows a thing or two about great tear-ups. He is expecting something good.

Steve Bunce
Boxing pundit on BBC Radio 5 live at Bramall Lane

Spence already had a big challenge with his walk to the ring. He's fought at gymnasiums that you've never heard of. Kell's been here, but Errol hasn't.

All of the Lights, from Kanye West, is played out and that can only mean one thing. Here comes the champion. Here comes Kell Brook.

The stadium is lit up with camera phones with the locals desperate to get a snap of the local hero.

The noise rises and rises and rises until the moment Brook climbs through the ropes.

Image source, Rex Features

BBC Radio 5 live

Just a quick reminder, press the play button at the top of the page to listen to BBC Radio 5 live commentary.

Join Mike Costello, Steve Bunce and Adam Booth for all the action.

Steve Bunce
Boxing pundit on BBC Radio 5 live at Bramall Lane

It's an interesting thing. There's an awful lot of people who think Kell should have taken a diversion and not gone all the way back down from middleweight to welterweight to avoid Errol Spence. Kell's a twelve round fighter. I'm convinced he can last. I think he'll be looking to take it long.

It was a tricky assignment for Kell from day one, it was always going to be a dangerous fight. It's an incredibly risky night's work.

There are so many elements to this fight that we don't know. So many parts about Errol Spence that we just don't know. There are an awful lot of unknowns in this ring tonight.

Boos ring around the Bramall Lane stadium as American Errol Spence, a man, who let's not forget, is unbeaten, walks to the ring.

Luke Reddy
BBC Sport boxing reporter at Bramall Lane

Image source, .

A £10 slice of Bramall Lane history offers everything from stats on the fighters to pundit predictions.

One potentially key stat in here - and one that hasn't been talked about all too much - is the fact Errol Spence Jr will have a three inch reach advantage tonight. If he gets ahead, he should be able to use his jab to maintain distance and control, while Brook will be clambering for fighting space up close.

In the programme, WBC cruiserweight champion Tony Bellew discusses the fact Spence is defending an unbeaten record.

"No losses can be a valuable thing, to me it wasn't," says Bellew. "I'd rather have one or two losses on my record and know I fought the best."

Former super-middleweight champion Carl Froch adds: "Brook is now back down at welterweight so he should be looking to dominate and prove he is the best out there."

Neil Diamond's 'Sweet Caroline' launches itself around Sheffield United's home ground - the crowd predictably join in the sing-a-long.

That means it is very nearly time.

Luke Reddy
BBC Sport boxing reporter at Bramall Lane

Ever the showman, Prince Naseem Hamed is in the ring to work the crowd.

He hailed from the Ingle Gym of course, just like Kell Brook. The Sheffield gym prides itself on teaching good footwork.

It's believed such a skill will negate tricky styles such as the southpaw stance Errol Spence Jr will serve up.

Mike Costello
BBC boxing correspondent at Bramall Lane

There are two key factors in this fight. One is the talent of Errol Spence Jr. We've seen from the opposition he has faced so far that he is pretty special but he's never been hit as hard as he is going to be hit tonight, how he reacts to that will be key.

The other factor is how Brook has lost his weight. He has never been comfortable at this weight and we have seen boxers in the past struggle to come down when they have put weight on, especially if it is muscle. How he reacts to boiling down will be key.

I do have a feeling this will be really special. Brook has the experience, Spence has the talent. This is Brook's toughest ever challenge at welterweight.

Last-minute backstage preparations...

Kell Brook has had to lose 13 pounds and drop down two weight divisions from his previous fight, hence the gruelling 12-week training camp in Fuerteventura.

"I've put myself through it," he said of his preparations to face Spence.

"My team wanted me to move up to 154 (pounds) but I'm a stubborn guy, it took me all my career to get that world title and beat Shawn Porter. There's no way that I want to move up and just give that title up.

"You've got to take it away from me, rip it out of my hands. I'm passionate and this belt belongs with me. "I've made sure I've put myself through it. I got on top of my weight early in camp so I came here fit and healthy and firing on all cylinders."

Image source, Lawrence Lustig