Wladimir Klitschko is a fighter.
Wladimir Klitschko . He is a former world heavyweight champion of three major sanctioning bodies , having held the titles of the WBA , IBF , and WBO ( twice ) ; additionally he has held the IBO , Ring magazine , and lineal heavyweight titles . A strategic and cerebral boxer , Klitschko is considered to be one of the greatest heavyweight champions of all time , as well as among the hardest punching knockout artists in the history of the division ; his strong jab , straight right hand and left hook being his most formidable weapons . In 2006 , Klitschko regained a portion of the world heavyweight championship after stopping Chris Byrd in a rematch to win the IBF and IBO titles .