NATHAN Cleverly admits what should have been the crowning achievement of his life has turned into a nightmare week, even though he’s become a world champion.

The Cefn Fforest fighter is one of the hottest young stars in British boxing, undefeated and already a Commonwealth, British and European champion.

The 24-year old meets Poland’s Aleksy Kuziemski at the O2 Arena in London tonight after a wild week which has seen his title dream be both on and off and changing as frequently as the weather.

Cleverly was scheduled to challenge Juergen Braehmer for the WBO light heavyweight title but the German withdrew with an eye injury at short notice, much to the ire of promoter Frank Warren.

Warren appealed to the WBO to strip Braehmer of his title, which they did, and brought in undefeated domestic rival Tony Bellew as a new opponent as interim champion Cleverly was named as a new world champion, Wales’ 11th.

However, a turbulent press conference, halted when the two fighters traded insults and almost blows, was followed by more bad news for Cleverly, with Bellew declared unfit to fight by the British Boxing Board of Control on Thursday night.

Cleverly now faces little known Polish fighter Aleksy Kuziemski in the first defence of his title and admits that life was less complicated when he was working out equations as part of his Cardiff University mathematics degree course.

“It’s easier, I tell you – there are less problems doing the Maths,” he joked.

“This is boxing, though. I’ve seen it all before and had it done to me before. So here we are again.

“I’ll be fine. I’ll be focused and get on with business. It has all become a bit of a nightmare, but I have to get through this to move onto bigger and better things.”

Cleverly always maintained he wanted to win the belt in the ring rather than through political manoeuvring and added: “Winning and having that belt around my waist is when I can say I’m a true world champion.

“I can start celebrating then and only then.’’ Both fighters made the weight at the first time of asking yesterday, Cleverly tipping the scales at 12 stone, 6lbs and 10oz with Kuziemski 12 stone 6lbs and 12oz.

Kuziemski, 34, has a pro record of 23 fights with 21 wins, although Braehmer beat him in 2009.