Carmen Basilio, a genial onion farmer’s son who wrested the world middleweight boxing crown from Sugar Ray Robinson in 1957 and lost an equally epic, razor-edge rematch six months later, died Nov. 7 at age 85.

Edward Brophy, executive director of the Boxing Hall of Fame in upstate New York, said Mr. Basilio died at a Rochester hospital where he was being treated for pneumonia.

Mr. Basilio lived in the Rochester suburb of Irondequoit and was among the first class of hall of fame inductees in 1990, a group that includes Robinson, Muhammad Ali, Rocky Marciano, Joe Louis and Jake LaMotta.

Mr. Basilio’s ferocious battles with the likes of Billy Graham and Kid Gavilan riveted a nation during the age of black-and-white television. Hindered on his ascent by a reluctance to deal with mobsters, he took the welterweight title from Tony DeMarco in 1955 and added the middleweight belt near the close of a 13-year career.

With his crouching style, the 5-foot-6½ slugger relentlessly wore down his opponents with body blows. He had a straight-up, knuckle-rimmed uppercut all his own, a vicious hook and an ability to withstand terrible punishment. He rarely stepped backward.

“I gave them action; they loved to see action,” he told the Associated Press in 2007, still filled with delight at earning The Ring magazine’s “Fight of the Year” designations five years in a row, from 1955 to 1959.

Mr. Basilio’s storybook journey began April 2, 1927, on an onion farm in Canastota in central New York as one of 10 children of Italian immigrants. From age 5, he worked the rich black soil in all weathers, and the constant bending developed powerful thigh and stomach muscles.

After a stint in the Marines, Mr. Basilio turned pro in 1948. His early career was littered with setbacks.

He drew his first title shot in 1953 against Gavilan. He floored the Cuban great for the first time in his career, only to lose on a split decision. A rematch never came.

The ’50s were a golden age for boxing when thrice-weekly “fight nights” helped sell TV sets. But it also was a dark diversion directed by mob bosses. Mr. Basilio said he refused to cooperate with them and was repeatedly passed over for title bouts.

His second chance finally arrived against the newly enthroned DeMarco in 1955. When he stopped DeMarco in the 12th round, Mr. Basilio knelt in his corner, repeating “I did it! I did it! I did it!”

In their next duel, a left hook from DeMarco almost lifted Mr. Basilio off his feet. He pirouetted, his legs buckled but somehow he stayed up. He KO’d DeMarco in the 12th.

Mr. Basilio stepped up to the 160-pound middleweight class against Robinson on Sept. 23, 1957. Four years earlier, Mr. Basilio was walking down Broadway in New York when he spotted Robinson with his entourage and introduced himself.

“He gave me a brushoff, and I lost my respect for him right then and there,” he recalled. “He was an arrogant guy.”

Mr. Basilio carried that grudge into their encounter in Yankee Stadium.

In the 11th round, he clobbered Robinson with 34 straight punches, pinning him against the ropes. Robinson rallied in the 12th but was hanging on at the end, and Mr. Basilio won on a 2-1 vote by the judges.

“You’re talking about the finest boxer of all time,” trainer Angelo Dundee told the AP before his death earlier this year, “and Carmen outboxed the guy. He beat him soundly.”

In the rematch in March 1958, Robinson regained the title in another close decision. A rupture above Mr. Basilio’s eye swelled to the size of a baking potato.

“I had to change my stance a little bit so I could see him,” he insisted, “but I thought I won the fight that night.”

Robinson’s refusal to fight a third time undermined Mr. Basilio’s drive, and his career (56-16-7 with 27 knockouts) ended in 1961 after three unsuccessful title shots against Gene Fullmer and Paul Pender.

He moved on to teach physical education at Syracuse’s Le Moyne College for 21 years and marketed beer for the Genesee Brewing Co. His gift as a raconteur won him legions of new fans at charity banquets, and even old foes came to revere him.

When DeMarco’s son died in a car crash in 1975, Mr. Basilio showed up for the funeral in Boston. “You don’t forget things like that,” DeMarco said in 2007.

“He belongs in any era, any time,” Dundee said of Mr. Basilio. “I would have to put him as one of the best.”

—Associated Press