by Edward Chaykovsky

According to IBF world heavyweight champion Charles Martin, he's in the best shape of his career.

Martin (23-0-1, 21KOs) captured the vacant title in January with a third round stoppage of  Czar Glazkov at the Barclays Center in Brooklyn, New York.

Joshua (15-0, 15KOs) will have the crowd on his side at The O2 Arena in London. The big puncher was last in the ring back in December when he knocked out domestic rival Dillian Whyte.

Martin is the world champion, but he's also listed as the big undercard. Joshua has looked unstoppable, although he's not faced a high level of competition. Most experts view the bout as a 50-50 proposition with either fighter capable of getting a knockout win from a single punch.

"The best camp I've ever had. I feel in the best shape I've ever been in. So, we good," Martin told Sky Sports. "I am peaked right now, we are just maintaining right now. All the hard work has been done. I am not going to wait to come over here to try and switch up anything. We are just riding it out now, I am in tremendous shape."

"This is my backyard. Wherever I go, I feel at home. I don't feel that I am coming into his den, wherever I take myself on this Earth is mine, I make it mine. Let them be fans of Joshua because when I knock him out on April 9 they are going to be Prince Charles Martin fans."