Uzbekistani boxer
His nickname is after Mike Tyson.
Co-WBA Heavyweight Champion with Nikolay Valuev since August 2008. Chagaev beat Valuev in 2007 to win the title outright, but was unable to fight Valuev twice in a rematch due to injury; Valuev won a share of the title by beating #1 contender John Ruiz.
(June 2009) Beaten by Wladimir Klitschko in a title fight before 61,000 at a soccer stadium in Gelsenkirchen, Germany. He was to fight Nikolay Valuev for the WBA title in May, but it was called off when doctors found Hepatitis-B antigens in his blood. But because the rules are different in Germany, he was allowed to fight Klitschko.