Klitschko was utterly dominant and tagged Rahman seemingly at will
Wladimir Klitschko successfully defended his WBO and IBF heavyweight titles as he clinically took ex-world champion Hasim Rahman apart in Germany.
From the opening bell in Mannheim the 32-year-old Ukrainian had Rahman in trouble with his piston-like left jab.
Klitschko won every round and first had Rahman on the deck in the sixth.
The American made it through the round but had nothing left in the tank and the referee stepped in early in the seventh to prevent further punishment.
"I thought I could land some punches earlier but it wasn't worth it because Hasim Rahman knew he was up against the best and he was really focused, you could see that," said Klitschko.
"He really hung in there and it wasn't easy."
Klitschko, younger brother of WBC champion Vitali, improved his record to 52 wins and three defeats.
Rahman, who slipped to 45 wins, seven defeats and two draws, caused one of the biggest upsets in boxing history when he knocked out Lennox Lewis in the fifth round of their world heavyweight title clash in South Africa in 2001.
London's former cruiserweight world champion David Haye, who made an impressive heavyweight debut against Monte Barrett last month, was ringside in Mannheim.
Elsewhere, American Kendall Holt retained his WBO light-welterweight title with a split decision over Demetrius Hopkins in Atlantic City.
Two judges gave the decision to Holt quite comfortably - 117-111 and 116-112 - with the third causing some surprise with a 115-113 call in favour of Hopkins.
It was a first defeat for Hopkins, the nephew of former middle and light-heavyweight champion Bernard Hopkins, while Holt is now in line for a unification bout next year against WBC champion Timothy Bradley.