WASHINGTON - Undefeated Shawn Porter stopped former world champion Paulie Malignaggi in the fourth round Saturday to retain his International Boxing Federation welterweight crown.
Porter improved to 24-0 with one draw by hammering Malignaggi before the all-American showdown was stopped 74 seconds into the fourth round, his 15th triumph inside the distance.
"I definitely needed this victory," Porter said. "To get it like that, to beat this guy, meant a lot."
Malignaggi, 33, fell to 33-6 in what might have been his final career bout.
"A really great fighter beat me," said Malignaggi. "If this is my last fight, I lost to a great champion."
In another world title fight, Unbeaten Peter "Kid Chocolate" Quillin kept his World Boxing Organization middleweight title with a unanimous decision triumph over Czech Lukas Konecny.
Both fights were on the undercard of the light-heavyweight unification bout between Bernard Hopkins and Beibut Shumenov.
Porter, 26, made the first defense of the title he took from countryman Devon Alexander last December.
"I knew everything he was coming with," Porter said. "He asked some questions and I got the job done."
Porter stunned Malignaggi in round two, bloodying his nose during a furious exchange in the center of the ring and later staggering him with a hard left to the head that Porter followed with a series of blows against the ropes that left "The Magic Man" lucky to escape the round.
In the early seconds of the fourth round, Porter sent Malignaggi to the canvas with two hard rights and a left, then moments later landed a pair of staggering rights that sent Malignaggi up against the ropes.
From there, Porter landed punches at will until referee Sam Williams stopped the punishment.
"We knew the right hand was going to be there all night. It was right there," Porter said.
"He wished me the best. He said no doubt he lost to a great champion."
- Third title defense -
Quillin made his third title defense, improving to 31-0 by near-perfect judges' scores of 120-108, 119-109 and 119-109.
"We can always throw more jabs. I can always move my head a little bit more," Quillin said of what needed improvement.
"I was able to get in there with a tough customer. He came to fight."
Konecny, who also lost his two prior world title fights, fell to 50-5.
"It was nothing that I didn't expect. I would have expected even a harder fight," Konecny, 35, said. "Quillin is a good champion but not a great one."
Quillin, 30, dominated from the start as the challenger's defensive style kept him jabbing and moving to penetrate in a slow-paced fight.
In the sixth, Quillin landed a hard right to the head of Konecny and the champion followed with two solid body blows and an uppercut in the seventh.
Quillin, who threw and landed more than twice as many punches as Konecny, bloodied the Czech's nose in the eighth as the last rounds settled into a monotonous pattern, the challenger taking hits and covering while waiting for brief chances to attack inside, generally just before the bell.
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