Vladimir Klitschko has kept his world heavyweight titles after stopping challenger Tony Thompson in the sixth round of a one-sided contest in Switzerland

The 36-year-old Ukrainian, who knocked out Thompson when they met four years ago, extended his unbeaten run to 16 fights, his last defeat coming when he challenged Lamon Brewster for the WBO title in 2004.

"It was easier this time, because I had more control," the boxer told journalists after the bout at the Stade de Suisse in Berne.

Thomson conceded he'd been outmatched, calling Klitschko "a great champion".

He went on to say: "You know, while he's fighting the top guys and amateurs, I had, you know, thirteen, fourteen amateur fights. So, I'm pretty much, if you go by your career, I'm pretty much still amateur and, unfortunately, you know, I wasn't able to get into the sport when my body was the best."

'Dr Steelhammer', as he is often referred to, has won 58 and lost three of his professional bouts, holds the WBA, IBF, WBO, IBO titles while his older brother Vitali holds the WBC title.