The Klitschko brothers, Wladimir and Vitali, have a stranglehold on the division, holding the WBC, WBO, IBF and IBO titles between them. But while one family is holding four titles, the other significant belt has two holders. For when Nikolay Valuev and Ruslan Chagaev step into the ring in Helsinki, Finland, tomorrow to contest the WBA title, they will both enter as champions.

They have met before, two years ago in Stuttgart, when Chagaev, from Uzbekistan, took the 7ft Russian giant’s title by winning a majority points decision. Chagaev made one successful defence, against Matt Skelton, of Great Britain, before injury intervened and the situation became messy.

A rematch with Valuev had already been postponed once when Chagaev suffered a freak injury while sparring, when he stumbled and suffered a complete tear of his Achilles. But, rather than strip Chagaev of the title, the WBA created a title for him - “champion in recess” - giving the Uzbek a year to get himself fit.

But, while Valuev got his hands back on his old belt, the situation got even more convoluted in February when Chagaev, not keen to face Valuev after a long period of inactivity, was allowed to defend his “champion in recess” title in February against Carl Drummond, an American. Now, though, the fragmented belts should be joined again - as long as it is not a draw.

There was no one more upset than Valuev when the rematch was first called off. In their first meeting, Valuev seemed to underestimate Chagaev, whom he towers over by nearly a foot, allowing the Uzbek to build an early lead that he clung on to as Valuev chased after him in the later rounds. “I am glad I will finally get the chance to set the record straight,” Valuev, 35, said. “I am very confident of success. I have improved a lot since the first meeting. This is certainly the most important fight of my career.”

Valuev responded to the defeat by switching trainers to Alexander Zimin. While Valuev will never lose the adjective hulking, under Zimin he has quicker hands and throws a greater variety of punches. “I have no doubts that Valuev will win,” Wilfried Sauerland, the Russian’s promoter, said. “He has improved a lot since the first meeting. His new coach has made him much better. He is well prepared and he will leave the ring as the winner.”

Valuev, though, is capable of boxing well below his best, as he showed in his last defence against Evander Holyfield in Zurich in December. Valuev had objected to being made to face the 46-year-old former champion and had seemed reluctant to even punch him. At the end of one of the worst bouts in heavyweight championship history, Valuev’s hand was raised and Holyfield’s camp cried “robbery”. Holyfield will be ringside tomorrow hoping to face the winner.

Never the most public of figures, Valuev has retreated from his home in St Petersburg to Kienbaum, a remote former East German sports camp, to train for the bout in isolation. “In St Petersburg the phone would ring every two minutes,” he said. “I could not walk on the streets without being recognised and asked for a signature.” The moments he is not in the gym, he is often alone boat fishing.

Meanwhile, Chagaev, who is 6ft 1in, recruited four giant sparring partners to acquaint himself with punching upwards. “My basketball team,” he calls them. “When I was hurt, Valuev simply got my world championship. This made me angry. Normally a boxer is named interim champion until a world champion is fit. That didn’t happen. Now I will correct this with my fists.”

Being the only non-Klitschko world heavyweight champion would put the winner in a strong position. Wladimir’s defence against David Haye on June 20 in Gelsenkirchen has captured the imagination and tomorrow’s bout is to be shown live in the UK on Setanta. The heavyweights are beginning to come back in vogue.

The heavyweight picture

The four claimants to the world heavyweight title all come from the former Soviet Union:

Wladimir Klitschko, 33, Ukraine The younger of the brothers holds the WBO, IBF and IBO titles, which he defends against David Haye, of Britain, on June 20.

Vitali Klitschko, 37, Ukraine Given WBC “emeritus” status when retiring as champion with an injury in 2005, a title he cashed in last year when regaining the WBC title from Samuel Peter.

Ruslan Chagaev, 30, Uzbekistan Beat Nikolay Valuev on a close decision for the WBA title in 2007, but made “champion in recess” when suffering a torn Achilles.

Nikolay Valuev, 35, Russia Regained the WBA title by beating John Ruiz in August after Chagaev had pulled out of a rematch twice.