Wladmir Klitschko left little doubt that he is boxing's best heavyweight champion as he recorded a seventh-round technical knockout of American Calvin Brock to retain his IBF heavyweight title at Madison Square Garden.

Making his first title defence since dethroning Chris Byrd last April, Klitschko (47-3, 42 KOs) started out slowly but began finding his rhythm with strong left jabs in the sixth round despite bleeding from a cut under his own left eyebrow because of a head-butt.

In the following round, the champion continued to attack and sent Brock to the canvas face-first with a straight right to the jaw.

Brock got to his feet at a count of seven with shaky legs before referee Wayne Kelly stopped the fight with 50 seconds remaining in the round.

"It took me time to get my rhythm and distance," Klitschko said. "I would fight anybody with a belt." Earlier in the round, Klitschko stung the contender with a left hook-right cross combination.

At the time of the stoppage, Klitschko was ahead on all three of the judges' scorecards.

Brock (29-1) was trying to follow the lead of fellow American Shannon Briggs, who dethroned WBO heavyweight champion Sergei Liakhovich last Saturday.

"He had a better jab than I thought," Brock said. "I saw the punch coming, but couldn't get out of the way. He's the best fighter I have ever fought. "I will be back."

Boxers from the former Soviet Union owned all four heavyweight title belts until last Saturday, when Briggs ended the Eastern European monopoly with a 12th-round technical knockout of Liakhovich in a WBO title fight in Phoenix.

In a women's bout, undefeated Laila Ali made her Garden debut with a fourth-round stoppage of Shelley Burton.

With her father, boxing icon Muhammad Ali, watching at ringside, Laila Ali (23-0, 20 KOs) had too much experience and firepower, easily handling Burton (8-3) before the fight was stopped with two seconds remaining in the round.

"I'm on a high fighting here," Ali said. "It feels great to be fighting in front of my father."