Klitschko brothers represented Ukraine at the 1996 Olympics, winning a gold medal in the super-heavyweight division. In 1996, when still an amateur, Vitali Klitschko tested positive for a banned substance and was removed from the Ukrainian boxing team. In June 1999, Vitali Klitschko won the WBO Heavyweight title from Herbie Hide via second-round knockout. He successfully defended the title twice before losing it to Chris Byrd. Six months later, younger brother Wladimir dethroned Byrd via lopsided points decision. He registered five successful title defenses, all by TKO until suffering an upset TKO loss to Corrie Sanders in March 2003. Vitali Klitschko lost
Vitali Klitschko leader. In the 2015 Kiev Mayoral election Klitschko was reelected with 66.5% of vote. For this he needed a second round of Mayoral elections between him and Boryslav Bereza after incumbent Klitschko scored 40.5% of the vote and Bereza 8.8% in the first round. (Bereza gained 33.51% of the vote in the second round of Mayoral elections.) Klitschko resigned as Petro Poroshenko Bloc chairman (on 26 May) after a new law barring a head of administration to be chairman or a member of a political party took effect on 1 May 2016. Klitschko is in favor of the Association Agreement