Wladimir Klitschko Universum Box-Promotion in Hamburg under the tutelage of Fritz Sdunek, often being featured on fight cards alongside his elder brother Vitali. After building an undefeated record of 24–0 with 22 KOs, he suffered his first loss to 24–13–1 Ross Puritty, in what was Klitschko's first and only professional fight in Ukraine. Puritty forced Klitschko, who had at that time not gone beyond 8 rounds, to punch himself out. Klitschko began to be overwhelmed in the 10th round and went down twice but was allowed to continue. At the start of the 11th round, with Puritty continuing to land hard punches,
Lennox Lewis vs. Vitali Klitschko title after passing on the chance to face the IBF's number one contender Chris Byrd. Instead, Lewis turned his sights on a possible match with Vitali Klitschko, who had become the WBC's number one contender after defeating Larry Donald by tenth-round technical knockout. In early 2003, however, negotiations for the fight fell through and Lewis began looking into a lucrative rematch with Tyson. The WBC ruled that a rematch with Tyson would be allowed on the basis that the winner would next defend their title against Klitschko. Tyson passed on the rematch, forcing Lewis to accept a less marketable fight