Heavyweights Ruslan Chagaev and Alexander Povetkin square-off in Erfurt, Germany, on Saturday with the WBA world title up for grabs and the chance to fight undisputed champion Wladimir Klitschko. Klitschko earned a unanimous decision over Britain's David Haye in Hamburg at the start of July to add Haye's WBA belt to his IBF and WBO crowns. After his victory over 12 rounds, the WBA promoted him to super champion status, meaning the belt is now vacant and whoever wins at Erfurt's Messehalle will have a chance to challenge Klitschko for the Ukrainian's belts. "Saturday is finally the moment for which I have been waiting so long, I want to fulfill my dream of winning a world title," said Russia's Povetkin, the 2004 Olympic heavyweight champion, who is unbeaten from 21 fights with 15 knock-outs. "Ruslan is a strong-willed athlete who never gives up, he has a real warrior spirit." This is a curious bout between two boxers who have struggled with injuries in recent years. Chagaev, 32, won the WBA heavyweight title in Stuttgart in April 2007 when he beat Russian giant Nikolai Valuev with a majority decision. But a torn achilles tendon injury in 2008 saw him lose the belt before he lost a title-fight to Klitschko in Gelsenkirchen in June 2009 after retiring in the ninth round. "I've been waiting for a second chance to win the title and it is imperative that I use it," said Chagaev, who hails from from Uzbekistan. Povetkin, 31, has twice lost the chance to fit Klitschko: the first time he missed out with an ankle injury, the second time he did not sign the final contract. "It was not about money at that time, both sides could not agree on the details of the contract," the Russian told SID, an AFP subsidiary. "But for now only the fight against Ruslan counts." Unusually, neither fighter opted to take Wednesday's final press conference into a war of words with an air of respect between the pair. "We will only duel on Saturday," said Chagaev, who has 17 knock-outs from 27 victories with just the one defeat.