NEW PALTZ, N.Y. - Floyd Patterson was small for a heavyweight, but that never stopped him from taking on the giants of his time. Good enough to become the first two-time heavyweight champion of the world, he wasn’t big enough to avoid taking beatings from Muhammad Ali and Sonny Liston.

Patterson died Thursday at his home in New Paltz, N.Y., at the age of 71. He had Alzheimer’s disease for about eight years and prostate cancer, nephew Sherman Patterson said.

A shy, quiet man, Patterson was a popular champion long after he retired, getting big ovations at fights. He was cast as the good guy in bouts against Liston and Ali, but was knocked out twice in the first round by Liston and stopped twice by Ali.

Patterson won fans because he had a big man’s punch, but a small man’s jaw. He could punch with the best heavyweights, knocking one opponent down 11 times in a fight. But he was also down a total of 21 times during his career, including seven times in an embarrassing loss to Ingemar Johansson, in 1959 at Yankee Stadium that cost him the heavyweight title.

“They said I was the fighter who got knocked down the most, but I also got up the most,” Patterson once said.

Patterson would come back to beat Johansson and become the first man to regain the heavyweight title, then would beat him again in a third fight despite being knocked down twice in the first round.

Patterson, who won a gold medal as a middleweight in the 1952 Olympics, weighed only 182 1/4 pounds when he beat Archie Moore for the heavyweight title in 1956. He was still only 188 1/2 pounds when he was stopped in the seventh round by Ali in his last fight in 1972.

That was big enough against the fighters of the late 1950s, but Liston demolished Patterson when they met in 1962, stopping him in the first round in Chicago to win the heavyweight title.

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Patterson said years later that President Kennedy had urged him not to fight Liston, who was reputed to be handled by mobsters.

“I’m sorry, Mr. President,” Patterson said he told Kennedy. “The title is not worth anything if the best fighters can’t have a shot at it. And Liston deserves a shot.”

Patterson was so embarrassed at being knocked out in the first round of his first fight with Liston that he donned fake glasses and a beard to avoid being recognized. Liston had no trouble remembering who he was when they met a second time 10 months later in Las Vegas and Patterson was stopped in the first round again.

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“He was very quick, next to Ali he was the fastest guy I fought,” said George Chuvalo, who lost a decision to Patterson in a hotly contested fight that Ring Magazine named fight of the year in 1965.

Patterson fought for 10 years after losing his title to Liston, getting three more shots at the title but never regaining it.

He fought Ali in 1965, lasting until the 12th round despite taking a beating from the champion, who was angry because Patterson called him by his given name, Cassius Clay.

During the fight, Ali toyed with Patterson, peppering him with jabs and right hands, all the time asking, “What’s my name?”

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Former Ali business manager Gene Kilroy said the two reconciled in the early 1970s when Patterson came up to Ali while he was eating and said, “Hello, Muhammad Ali.” They embraced and remained friendly after that.

“Ali always thought he was a real nice guy,” Kilroy said.

Patterson’s last fight was also against Ali, who stopped him on cuts and swelling on his face in the seventh round in 1972.