Ruslan Chagaev has described Saturday's WBA heavyweight title fight as arguably the most important of his career as he prepares to square off with former Olympic champion Alexander Povetkin. Chagaev and Povetkin meet in Erfurt, Germany, with the WBA belt 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. "This is probably the most important fight of my life," said Uzbekistan's Chagaev, who has 17 knock-outs from 27 victories with just the one defeat. "I have given no thought to defeat." Chagaev, 32, is fighting again for the same title he took from Russian giant Nikolai Valuev in Stuttgart in April 2007 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. Against Klitschko, he climbed into the ring under prepared as a late replacement after original opponent Haye pulled out of the fight, but this time there is no mistake with 106 rounds of sparring under his belt. "I am perfectly prepared and will give everything," said the devout Muslim and father of two sons. "Only the Lord knows how the fight will end, of course, I can go over twelve rounds, but I'll try to end the fight prematurely." Victory on Saturday would give Chagaev another shot at Klitschko. "I've already conquered the world's best, and I hope that things go well at the second attempt," said Chagaev. But he faces a tough task against the unbeaten Povetkin. "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 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."