MANNHEIM, Germany — Wladimir Klitschko defended his IBF heavyweight crown by stopping Hasim Rahman in the seventh round at SAP Arena last night.

Klitschko hit the shorter, older and heavier Rahman at will throughout, and after landing a left-right-left combination against the cornered American, referee Tony Weeks stepped in to end the contest 44 seconds into the seventh round. Rahman didn't appear upset.

"He knew this was his chance," Klitschko said, "I was surprised, but he was much slower."

Klitschko had knocked down Rahman in the previous round with successive left hooks.

The technical knockout in Klitchsko's sixth defense of the IBF belt — and third this year — improved the Ukrainian-born fighter to 52-3 with 46 KOs.

"He fought a very smart, intelligent fight," said Klitschko's trainer, Emanuel Steward.

Rahman, the two-time heavyweight champion who stepped in as a replacement opponent last month, struggled to get inside the taller Klitschko's reach, and dropped to 45-7-2.

The fighters started out fast and light on their feet, but it soon became apparent that Rahman was struggling to overcome the 3 1/2-inch height advantage enjoyed by the champion. Rahman had to lean in, and Klitschko easily fended off his punches.

Rahman did little more than lean on the ropes for a time and guard his face as Klitschko sought his opening.

"Wladimir was very smart not to throw too many punches and to be very patient and to work behind his left jab," Steward said.

Rahman looked reinvigorated in the fourth round, using his whole torso to make ambitious attacks, often connecting with Klitschko's body.

But he rarely landed blows above Klitschko's shoulders, and the consequences were clear when Klitschko dropped Rahman early in the sixth with two hard lefts to the side of his head.

Rahman got up but spent the remainder of the round in the corner, taking a sustained beating.

Another flurry at the opening of the seventh ended Rahman's challenge.

Klitschko also retained the minor WBO and IBO belts.

He was originally scheduled to face Alexander Povetkin (16-0), but the Russian pulled out with an ankle injury.

Klitschko cited Povetkin along with fellow Russian Nikolai Valuev and American Cristobal Arreola as signs that heavyweight talent is improving.

He also mentioned British boxer David Haye, who monopolized the post-fight press conference with a challenge to Klitschko's older brother, Vitali.

"I want to fight him because he's the big one," Haye said. "He in my opinion is the best fighter."

Vitali Klitschko, who reclaimed the WBC heavyweight title in October by stopping Samuel Peter, said he might fight Haye in 2009.

"We'll see," Vitali Klitschko said. "I would gladly fight against him."

On the undercard, former heavyweight champion Riddick Bowe made a modest comeback with an eighth-round decision over Germany's Gene Pukall. It was just the third fight in a decade for the 41-year-old American and his first in three years.

Bowe (45-1, 33 KOs) had been training in Germany since September in an effort to get his stamina up and his weight down. The work paid off in the ring, where he kept up with the 33-year-old Pukall (14-13-2, 12KOs) and bested him with a stream of careful head shots.