Vladimir Klitschko on his way to victory over Chris Byrd

The 30-year-old dominated the fight from the second round and twice knocked Byrd to the canvas to claim the belt.

Klitschko knocked Byrd down in the fifth with a powerful combination before flooring him with a flurry of punches two rounds later.

A disorientated Byrd got to his feet but the referee stopped the bout.

The American was bleeding from a cut above his left eye and had swelling around his nose and both eyes.

I want to conquer the other titles in the category, that's for sure Vladimir Klitschko

"I was never in the fight," said Byrd. "He's a big guy, he's strong and I didn't hit him at all."

Klitschko improved his record to 46-3 with 41 knockouts and the Ukrainian has now set his sights on unifying the heavyweight division.

Serguei Lyakhovich of Belarus holds the WBO belt, Russian Nikolay Valuev is the WBA champion while Hasim Rahman owns the WBC belt.

"I want to conquer the other titles in the category, that's for sure," said Klitschko, whose elder brother Vitali, a former WBC champion, retired last year.

Klitschko's Mannheim win is not the first time he has beaten Byrd to a title.

In 2000 he beat the American to claim the WBO crown in Cologne before losing that to South African Corrie Sanders three years later.

Byrd had beaten Evander Holyfield to take the vacant IBF title in 2001 which he had held onto before Klitschko's win.