By Edward Chaykovsky

In one of the bigger fights on the year, former division ruler Wladimir Klitschko will attempt to pull off an upset win on April 29, when he travels to the UK to face IBF champion Anthony Joshua before a rabid British crowd of 90,000 fans.

The vacant WBA, IBO belts will also be at stake in the contest.

Klitschko, who will be 41 years old by the time he steps in the ring, will be coming off the biggest layoff of his long pro career. The veteran has been inactive since suffering his first career defeat in over ten years, when he was upset by Tyson Fury in November of 2015.

There was already one big upset this past Saturday in the heavyweight division, when former Klitschko opponent David Haye was stopped in eleven rounds by Tony Bellew, who was moving up from the cruiserweight division.

For the first time in well over ten years, Klitschko is the perceived underdog against an undefeated Olympic gold medal winner who knocked out all 18 of his opponents in seven rounds or less.

Should he suffer another defeat, Klitschko career is likely over. But if he wins, Klitschko will hold three world title and most experts will once again regard him as the top man in the heavyweight ranks.

Speaking to Johnny Nelson and Adam Smith on Sky Sports News HQ, he said: "I honestly asked myself 'do I really like what I do?' and I said 'no Wlad, I actually love what I do'. This is one of the biggest challenges I've had in my life - coming back after an 18-month break and fighting a young champion, really talented, athletic and all of this.

"I'm the underdog in this fight and this is actually exciting for me. I haven't been in this situation for such a long time. I feel young and challenged. I'm the official challenger. Great! I want to leave the ring as the champion and the winner of this fight - that's my obsession. I'm obsessed about it. Then afterwards we can count things like being three-time world champion, the belts on the line, such a big stadium, such a great opponent, one of the rising stars...

"I'm turning my face to a challenge. Many people think I'm crazy - I'm going to be 41 and I'm fighting a guy much younger, so strong, scary, knocks everybody out. I'm showing my face to the challenge - I love it. I'm obsessed with what I'm doing."