Klitschko brothers 5 months & 13 days. Vitali retained the WBC Heavyweight Championship until 15 December 2013, relinquishing his belt in pursuit of his political aspirations in his native Ukraine. The Klitschko brothers jointly run the professional boxing promotion companies ""K2 Promotions"" and ""K2 East Promotions"", as well as the ""Klitschko Brothers Fund"", a charity organization. They appear together on German TV shows and commercials, have a website shared between them, and support each other's training and fights. After Vitali's retirement, Wladimir continued to reign as champion & successfully defend all remaining title belts except for the WBC belt. He eventually lost
Vitali Klitschko vs. Chris Byrd of the fight with Byrd being elusive and making himself a difficult target. After 9 rounds Vitali had suffered a torn rotator cuff and despite being clearly ahead on the scorecards (88-83, 88-83, & 89-82) he retired on his stool handing the win to Byrd. Harold Lederman, HBO's unofficial judge, had Klitschko ahead 88-83 at the time of the stoppage. Vitali's status as a rising star of the Heavyweight division took a knock after this with HBO commentator Larry Merchant said, "He doesn’t have the mentality of a champion. I can hardly believe what I just saw." Byrd's first defence