Wladimir Klitschko is a Ukrainian former professional boxer who competed from 1996 to 2017. He held multiple heavyweight world championships between 2000 and 2015, including unified titles between 2008 and 2015. During this time he also held the International Boxing Organization (IBO) and Ring magazine titles.
A strategic and intelligent boxer, Klitschko is considered to be one of the greatest heavyweight champions of all time. He was known for his exceptional knockout power, using a strong jab; straight right hand; and left hook, quick hand speed, formidable physical strength (which he often employed when clinching opponents), and his athletic footwork and mobility – unusual for boxers of his size.
As an amateur, Klitschko represented Ukraine at the 1996 Olympics, winning a gold medal in the super-heavyweight division and ending his amateur run with 134 wins and 6 losses. After turning professional later that year, he defeated Chris Byrd in 2000 to win the World Boxing Organization (WBO) heavyweight title. Klitschko's first reign as champion ended in an upset knockout loss to Corrie Sanders in 2003, which was followed by another upset knockout loss to Lamon Brewster in 2004.