NEW YORK (Reuters) - Former world heavyweight boxing champion Floyd Patterson, who became the youngest boxer to gain the title when he knocked out Archie Moore in 1956 at the age of 21, died on Thursday. He was 71.

Patterson, who had suffered from Alzheimer's disease and prostate cancer, died at his home in New Paltz, New York.

He had three famed clashes with Sweden's Ingemar Johansson in a long career that stretched from his first great professional success against Moore through bouts against Sonny Liston and Muhammad Ali.

"Of all the men I fought, Sonny Liston was the scariest, George Foreman was the most powerful, Floyd Patterson was the most skilled as a boxer," Ali once said.

Elected to the International Boxing Hall of Fame in 1991, Patterson was small for a heavyweight and used a peek-a-boo style with his gloves held high in front of his face, using his quickness to defeat heftier opponents.

New York Gov. George Pataki saluted Patterson, who was born in Waco, North Carolina, and raised in the New York City borough of Brooklyn.

"Floyd Patterson was a world champion athlete and an inspiration to many Americans," Pataki said in a statement. "From his signature style in the ring to his support for amateur athletics later in life, Floyd Patterson was truly the 'gentleman of boxing.'"

After an amateur career that included Olympic gold as a middleweight in 1952, Patterson turned professional. On November 30, 1956, he claimed the world heavyweight title vacated by the retirement of Rocky Marciano by knocking out Moore in the fifth round.

Patterson was 21 at the time, making him the youngest heavyweight champion until 20-year-old Mike Tyson beat Trevor Berbick for the title in 1986. Patterson and Tyson were both trained by Cus D'Amato.

Following four title defenses, Patterson lost the crown in 1959 when he was knocked down seven times in the third round. losing to Sweden's Johansson in New York.

One year later, Patterson became the first heavyweight champion to regain the crown when he returned to the Polo Grounds to knock out Johansson in the fifth round.

Patterson won a third bout against Johansson in 1961, stopping the big Swede in the sixth round.

He made one more successful defense before losing the title to fellow-American Liston by a first-round knockout in 1962.

Patterson fought three more times for the heavyweight title. He was knocked out again in the first round by Liston in 1963, was stopped after a 12-round beating by Muhammad Ali in 1965, and lost a 15-round decision to Jimmy Ellis in 1968.

Ali carried a grudge into the 1965 bout against Patterson.

He was angry that Patterson refused to call him Muhammad Ali, and continued to refer to him by his birth name, Cassius Clay. Instead of finishing him off in the one-sided fight, Ali mocked and punished Patterson before stopping him in the 12th.

Patterson retired in 1972 at age 37 with a professional record of 55-8-1 and served as New York state athletic commissioner.

The ex-heavyweight champion later adopted a young boy who aspired to be a boxer and helped mold Tracy Harris Patterson into a world super bantamweight champion. He also counseled troubled children for New York State family services.

Patterson once revealed his motivation when he said: "The fighter loses more than his pride in the fight; he loses part of his future. He's a step closer to the slum he came from."

RIP Floyd Patterson .

Man. Bless him Lord! Give him and his family peace.

ShySlantedEye1 said:

yeah, he was sick for quite a while.

Rest well.

What a gent I'm sure Cus will be one of the many who comes to receive him at the gates

Rest easy, Champ

RIP Floyd, a true great. Never ducked anyone.