“I’m sure Khan’s good,” Malignaggi says

New York: The boxer Amir Khan spent late April and early May in Vancouver, British Columbia, his entry into the United States delayed while he obtained a work visa. By Saturday, Khan had gone to work here for the first time, and his opponent, Paulie Malignaggi, wished the stopover had been longer.

Khan justified the hype he brought with him from England. He punished Malignaggi at the outset and pummeled him throughout, registering a technical knockout 1 minute 25 seconds into the 11th round.

In a one-sided triumph that was nearly stopped earlier, Khan retained his World Boxing Association super lightweight title in front of 4,412 at Madison Square Garden’s smaller theater. Afterward, he said he planned to remain in that division until he could unify the belts, and that he will fight in England in July.

“I was just amazed,” said Richard Schaefer, the chief executive of Golden Boy Promotions. “The speed. The combinations. The power. He’s the total package.”

Khan (23-1, 17 knockouts) landed more jabs, more power punches and more total punches (259 to 127). He won every round and forced Malignaggi (27-4) to deliver an opinion opposite from all the criticism he levied across an ocean the past few months.

Malignaggi took questions with a swollen left eye and bruised face. He said that of the four fighters he has lost to, he considered two, Khan and Miguel Cotto, to be truly elite — high praise for Khan, who won a silver medal at the 2004 Olympics and does not turn 24 until December.

“He’s a terrific fighter,” Lou DiBella, Malignaggi’s promoter, said. “He’s a tremendously talented kid.”

Khan dictated the pace in the early rounds, stalking Malignaggi, throwing punches with more potency and frequency. In the second round, Khan landed a four-punch combination that sent Malignaggi backward, and by the middle of the next round, Malignaggi’s left eye appeared swollen.

The fight continued in that vein, with the man nicknamed King Khan playing the aggressor. In the fourth round, Khan ducked, then bounced Malignaggi’s head backward with a powerful right hand.

Khan brutalized Malignaggi repeatedly with that hand, with jabs and overhand rights and straight rights, until every round seemed almost exactly like the one before. When Malignaggi adjusted in Round 7, Khan smacked him repeatedly with the left.

Soon after, doctors checked on Malignaggi between rounds. He begged to go back out for No. 11. The referee stopped it halfway through.

“We had to break him down slowly,” Khan said. “From Round 9, I knew I wasn’t letting him off. I had to keep the pressure on him.”

The pressure started, in large part, through a Twitter feud escalated at Friday’s weigh-in, when the fighters’ camps exchanged shoves and punches before security stepped in. DiBella stalked through the room afterward, incensed, his voice rising.

So went another fight week, even if this was not exactly a normal fight.

For starters, it was Khan’s debut in the United States, where he is somewhat unknown. Khan’s low profile here stands in stark contrast to his celebrity status in England, where he once met former Prime Minister Tony Blair and carved out a résumé that shaped his candidacy as one of boxing’s next potential stars.

Khan’s only loss came by knockout at the bruising hands of Breidis Prescott, who won his bout on Saturday’s undercard. After that defeat, Khan hired Freddie Roach, perhaps boxing’s best trainer, who steered Manny Pacquiao toward greatness. Still, questions lingered.

“I’m sure Khan’s good,” Malignaggi said on Wednesday. “But he’s unproven at a high level. He hasn’t got one major victory on his record. They handed him a world title, after he got knocked out.”

Malignaggi presented a real test, even though Khan entered the bout the heavy favorite. Malignaggi once held his own super lightweight title belt — he lost to Ricky Hatton in 2008 — but he fell so far so fast that he made only $10,000 in his next fight and wondered if his boxing days were numbered.

Malignaggi also hired a new trainer, Sherif Younan. As Malignaggi rebuilt his reputation — winning his rematch against Juan Diaz in December to rise back into title contention — he credited Younan.

Malignaggi said this fight, held near his native Brooklyn, represented redemption. But he also knew the brutal truth: another loss, and even his promoter said fights of this magnitude would likely be out of reach.

Afterward, Malignaggi was not sure what would come next. Off they went, two fighters headed in opposite directions. King Khan had come here and delivered. His message was emphatic.