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,
Wladimir Klitschko out of the fight due to not being fully recovered from a torn abdominal muscle. On 5 March, it was instead announced that the highly anticipated fight against David Haye would take place on 2 July 2011. The fight was contingent on Klitschko's recovery from a torn abdominal muscle injury. The contract was written so that if Klitschko was not fully healed, then Haye would fight his brother, Vitali. Klitschko fought David Haye in a heavyweight unification fight for the WBA (Super), WBO, IBF, IBO and "The Ring" Heavyweight titles. The fight took place at the Imtech Arena, Hamburg, Germany