Wladimir Klitschko retained his WBA, IBF and WBO heavyweight titles with a sixth-round stoppage of Tony Thompson in Bern on Saturday night.
Thompson never recovered from a big right hand in the fifth and the referee ended the contest 2:56 into the sixth after the 36-year-old again floored the 40-year-old mandatory challenger.
The Ukrainian was always in control of the bout after a cagey opening round and improved his career record to 58-3, 51 by KO.
Klitschko knocked Thompson out in the 11th round when they met in 2008.
