Two rounds gone, two 10-9s to Brook. He has not been challenged so far.

Brook is popping out the left jab and there's some marking under the right eye of DeLuca.

He tries to change his approach with a dash forward, but Brook sees the swinging left coming and avoids it.

A left-right-left hook from Brook is some good work early in the second. DeLuca is already looking a bit out of his depth.

A lovely straight right rocks the head of DeLuca back, Brook then forces him back on to the ropes late on in the first and that cranks up the noise levels.

All Brook in the opener. Little to shout about from the American.

Brook, firmly planted in the middle of the ring at the Sheffield Arena, looks to impose himself from the off. Just the one loss for the American Mark DeLuca, but this is a big jump up in class for him today.

Here we go. A fight involving Special K is always special.

Remember to let us know your thoughts on this one. Can Brook win a world title for a second time?

You know it's a bit special when Michael Buffer has the microphone in his hands.

"Fight fans are you ready? For the thousands in attendance and the millions watching around the world, from Sheffield, England, let's get readdddddyyyyyyyyy to rumble."

• Age - Brook 33, DeLuca 31
• Fights - Brook 40, DeLuca 25
• Wins - Brook 38, De Luca 24
• Losses - Brook 2, DeLuca 1
• Weight - Brook 10st 13lbs 12oz, DeLuca 10st 12lbs 12oz

Mark DeLuca's already in the ring.

The lights drop in the Sheffield Arena. "All of the lights," from Kanye West comes over the speaker system. It has been one of the anthems of British boxing over the last decade. It still remains spine-tingling.

Kell Brook has fought the very best and reached the top of the world. A superfight with Amir Khan never happened, despite Brook doing everything he could to get it on, but can Brook catapult himself back to the world title level?

The forgotten man of British boxing is back.

Let's hope, it's not just for one last time.

It's all or nothing for Kell Brook tonight, who has said he will announce his retirement in the ring tonight if he loses to Mark DeLuca.

"This last chapter of my career, I'm giving it my all," Brook said. "If I get beaten I can walk away with my head high, knowing I have given everything."

He told the 5 Live Boxing with Costello & Bunce podcast: "If I get beaten by DeLuca, I will announce my retirement in that ring. If I can't beat him, what am I doing?"

Steve Bunce
BBC Radio 5 Live boxing pundit

Saying Kell Brook is a forgotten man is not too strong.

He turned pro at 18 and got £300 for his first fight. For his third fight, he didn't even get paid. He started his career facing obscurity and hardship.

I've had him on a dozen things and he's talked about walking away. He has been in some black, hellish holes. I have to be honest, by about the summer of 2017, I thought it might have been all over for Brook.

Five-minute warning time. Otherwise known as 'Sweet Caroline', by Neil Diamond.

Mike Costello
BBC Sport boxing correspondent

It is hard to escape the notion that Kell Brook has become the forgotten man of British boxing.

I remember being at one of the very first news conferences he was at after joining forces with promoter Eddie Hearn. People were saying 'this is the special one' and 'this is a very special kid'.

He went on to win the British title, then, in one of the single best wins ever by a British boxer, he beats Shawn Porter in the US. That was one of the great wins.

Next up, it's the main event. Kell Brook versus Mark DeLuca. Let's crank-up the build-up.

Some quotes from promoter Eddie Hearn: "That was an atmosphere worthy of any main event. Eva Wahlstrom is a big star in her country and this is a great story. Boxing changes lives. We have a rough diamond here in Terri Harper."

Here is the new world champion, Terri Harper: "I'm speechless, thank you to everyone who came to watch me. The timing was right, I had a lot of pressure on me. I'm 23 years old and I've just done this, I've just made history.

"I never thought I would get to this point if I was to be honest. After every fight I'm not happy with my performance. It was a tough fight. I went back to my boxing."

Trainer Stefy Bull adds: "Tonight is the start of something very special."

The judges have it wider than I thought, with one calling it 98-91 to Harper, with the other two judges giving her it by 99-90 margins.

Terri Harper, from Yorkshire, is the new women's WBC and IBO world super-featherweight champion.

What a night for her.