The Ukrainian clearly dominated the first five rounds, making repeated contact with his strong left jab that largely went unanswered.

Brewster seemed to be standing up to the constant punishment, but two massive left-right combinations in the sixth round rocked the American. Before the seventh could start, Brewster's trainer, Buddy McGirt, flapped his towel and referee Sam Williams called the fight.

"His opponent didn't really do anything to make him worry," said former heavyweight champ Lennox Lewis, who was ringside for HBO. "Lamon Brewster didn't do what he did in the first fight and push Wladimir and also Lamon Brewster stood in one spot and allowed himself to be an easy target for Wladimir's great, powerful jab, which at the end of it really won the fight for him."

When the two met in 2004, Brewster stopped Klitschko with a fifth-round TKO to win the vacant WBO championship in Las Vegas.

Klitschko dominated that fight early on and knocked down Brewster in the fourth round, but the American was saved by the bell. Two left hooks by Brewster in the fifth turned it around.

On Saturday, Brewster was returning after a yearlong absence following a loss to Sergei Liakhovich in April 2006 during which the American suffered a detached retina in his left eye that required surgery. He returned from his layoff to fight Klitschko without even a warmup bout.

His time away from the ring was apparent. While Klitschko was pure muscle, Brewster was clearly carrying extra weight around the middle. Before his injury, Brewster successfully defended the WBO heavyweight title three times _ against Kali Meehan, Andrew Golota and Luan Krasniqi.

Klitschko's record is now 49-3, with 44 knockouts, while Brewster is 33-4 with 29 KOs.

The Ukrainian weighed in at 244 pounds, 15 pounds more than his opponent.