Vladimir Klitschko retains heavyweight titles after defeat of Thompson

World heavyweight champion Wladimir Klitschko (R) punches Challenger Tony Thompson of the United States during their boxing fight on late July 7, 2012 at the stade de Suisse stadium in Bern. Klitschko defended his IBF, WBA and WBO heavyweight titles against Thompson in a one-sided bout stopped in the sixth round. AFP / FABRICE COFFRINI

BERN, Switzerland — Vladimir Klitschko defended his IBF, WBA and WBO heavyweight titles against American Tony Thompson in a one-sided bout stopped in the sixth round here on Saturday.

The 36-year-old Klitschko was winning his 58th fight, 51 by KO for only three defeats.

Thompson, 40, survived a fifth round count after hitting the canvas with a jab from Klitschko, but his number was up after a series of punches forcing the referee to stop the contest in the next round.