By Edward Chaykovsky

IBF welterweight champion Kell Brook (36-1, 25 KOs) is a happy man, after 17,000 tickets got snapped up in the first day of sales for his mandatory defense against unbeaten Olympian Errol Spence (21-0, 18 KOs).

The anticipated fight takes place in Brook's backyard of Bramall Lane in Sheffield. Sky Sports Box Office will carry the fight in the UK, while Showtime has the television rights in the United States.

"I've had a load of messages, loads of calls today, everybody wanting these tickets. Everybody has been queuing to Bramall Lane, so it’s first come first served. You want to get down there and get your tickets, because this is a historical fight at The Lane. We haven't had a big fight since 84. I can’t wait to fill the stadium back up," Brook told Sky Sports.

In his last fight, Brook moved up by thirteen pounds to the middleweight division to challenge division ruler Gennady Golovkin at the O2 Arena in London. He suffered his first career defeat, when a fractured orbital bone forced his corner to stop the contest in the fifth round.

Brook believes he is back at his natural weight, despite his handlers pleading with him to abandon the IBF title to move up to junior middleweight.

"I think after being in such a massive fight, I know the pressure of walking into a big arena, packed out and being in there with a big puncher. I’ve learned a lot from that fight and I’ve come back from that. It made me work a lot harder and I never want to suffer that kind of defeat again," Brook explained.

"I'm more at my natural weight. I moved up to middleweight to fight Golovkin....... a big, big puncher at middleweight. I’m more at my natural weight. I’m big, strong and healthy. I’ve never been beaten, never been looked to be beaten at welterweight - so I’m excited to back down to my natural weight."

To make a big statement, Brook is hoping to not only beat Spence - he wants to knock the undefeated challenger out.

"That’s what I’m going for [a knockout of Spence]. It’s going to be fireworks. All I can say is it’s the best fighting the best. Errol Spence, they are saying massive things about him in America, and I'm number one, I'm the champion. So its the best fighting the best and fans are in for a fantastic night, a packed out 25,000 arena at Bramall Lane. You're going to see everything in this fight.. speed, power, aggression," Brook said.

"I can't wait for the challenge. I’ve heard big things about this Errol Spence. They built him up in America. He’s my mandatory challenger. He’s coming to fight. He’s ticked all the boxes so far for everyone they’ve put in front of him, but this time he’s boxing against me. All of my fans can’t wait for me to get my hands on him, to show him them a massive, massive fight down there in Bramall Lane. I can’t wait to lock horns with him on May the 27th."