After plowing through the cruiserweight division and becoming only the fourth fighter in the four-belt era to become an undisputed champion, Usyk made his heavyweight debut last October. It took the 33-year-old a few rounds to get his feet wet, but he got on track to stop late replacement Chazz Witherspoon in the seventh round. The win had been expected to vault Usyk into a position to face the winner of the rematch between Anthony Joshua and Andy Ruiz since he is the designated mandatory challenger of the WBO. Joshua beat Ruiz in December to regain the WBO, WBA, and IBF belts. But the IBF mandatory is due first, so Joshua will face Kubrat Pulev on June 20. Should he emerge victorious, he will take on the Usyk-Chisora winner.

Usyk (17-0, 13 KOs) is getting a significant step-up in competition this time around. Beating someone the caliber of Chisora will prepare him properly to compete for the heavyweight championship.

"Boxing in Manchester in 2018 was an amazing experience, now I get to do it in London at the famous O2 Arena, and I can't wait to fight in front of the British fans once again," Usyk said in a press release. "As a cruiserweight, I reached the highest heights as the undisputed champion, and now I am following the same path as a heavyweight.
 
"I expect a real test in Chisora. He is strong, tough, and resilient. I recall being an amateur and watching his fight with Vitali Klitschko. It seemed so big and far away. Now I am myself taking a fight against Chisora. I am working hard in my training camp to show a spectacular performance on May 23." 

Chisora (32-9, 23 KOs) is one of the most exciting fighters in the heavyweight division because of his all-action style, specifically his last two bouts, a second-round knockout win over Artur Szpilka and fourth-round TKO of David Price. Chisora has come up short against former heavyweight champions Tyson Fury (twice), David Haye, current interim WBC titlist Dillian Whyte (twice), and to-then WBC titleholder Vitali Klitschko via unanimous decision in February 2012.

When it comes to Usyk, Chisora expects another toe-to-toe battle as a win could put him right back in position to compete for heavyweight gold one more time.

"It's going to be leather," Chisora said on "Born Fighter". "I'm already taking dancing lessons. The guy is going to be on fire, man. He's going to be dancing, bro. He's going to be dancing. Where can you get guys who can be sparring like him? Nowhere. The guy is a dancer. He's going to dance. It's going to be hard. I'm not going to lie to you. I think this fight will be the hardest fight I've ever had. Not because the guy hasn't got power, but because of the accuracy of his punches and the way he chucks them. When he chucks them, he's unbelievable.

"I'm going to have to eat leather. I'm not going to lie to you. I'm going to eat leather. I'm probably going to take five before I get one in there, but it is what it is. I eat that s— for breakfast. The hunger remains, and the dedication is the same."