By Edward Chaykovsky

Promoter Eddie Hearn of Matchroom Sport is calling it a "50-50 fight" when Anthony Joshua (15-0, 15KO) steps in the ring for the biggest fight of his career. Joshua will challenge IBF heavyweight champion Charles Martin (23-0-1, 21KOs) on April 9th at The O2 Arena in London, live on Sky Sports Box Office.

Joshua, an Olympic gold medal winner who captured the British and Commonwealth heavyweight titles as a pro, is ready to join the elite ranks.

Martin captured his title last month with a third round stoppage of Czar Glazkov at the Barclays Center in Brooklyn, New York. Joshua has been out since December, when he knocked out domestic rival Dillian Whyte in the seventh round.

Hearn told Sky Sports News HQ: "I've seen odds fly around of Joshua v David Haye, Joshua v Tyson Fury and Joshua against Martin - everyone believes Joshua's the favourite in all those fights. The bookies say so. This fight, they make him a big favourite but I see this as a 50-50 fight.

"Martin has boxed twice as many rounds as Joshua, comes in as the world champion, is a 6ft 5in, awkward, southpaw with a big back hand. Joshua has to be disciplined - much more disciplined than the Dillian Whyte performance. I believe on April 9, he'll become heavyweight champion of the world. This is a guy that, if successful, can change the face of sport in Britain and boxing worldwide. He's got to beat Charles Martin, and that's the big risk. I think fans like the fact that he's diving in, he's taking a chance. It's something we considered very carefully because this is a risk, a big risk.

"Charles Martin called Anthony out, his promoters got in touch and Anthony said: 'You've got to get me that fight.' My job as a promoter and the jobs of his training team are to take the right fights at the right time. I asked the question: 'Can you beat Charles Martin now? That's the only thing that I want to know.' The answer is: 'Yes, we believe we can.' In that case, you have to take this shot and try and become heavyweight champion of the world. As big as Anthony Joshua is right now, imagine that man as heavyweight champion of the world. It's one of the biggest accolades in world sport."