He was the overwhelming favorite in his event, so much so that U.S. sportswriters covering the 1960 Summer Olympics said that if Americans won just one gold medal over the rival Soviet Union at that year’s Games, it would be his.

A skinny 19-year-old from Boston, John Thomas had been the first high jumper to leap 7 feet indoors, setting the mark when he was only 17. When the Summer Games in Rome began, he held the world record in the event, by then having cleared 7 feet more than 30 times. He had not been defeated in two years.

When he lost — perhaps inevitably, given his age and the pressure of the Olympics — Mr. Thomas was remarkably level-headed, telling reporters he was disappointed but proud to have won the bronze medal.

But the sports media castigated the teenager for choking. “I was called a quitter, a man with no heart,” he was later quoted as saying. “It left me sick.”

Four years later, Mr. Thomas and Valery Brumel, one of the two Soviets who had defeated him in Rome, shared an Olympic record at the 1964 Tokyo Games, each jumping 7 feet 1 3 / 4 inches. But Brumel, who had fewer missed attempts, again edged Mr. Thomas, taking home the gold to the American’s silver.

Coming at the height of the Cold War, the rivalry between the two men was intensified by the ideological struggle between the United States and the Soviet Union. But competing again and again against each other, Mr. Thomas and Brumel forged an improbable friendship.

Mr. Thomas, who became a community college coach and athletic director after he stopped competing, died Jan. 15 while undergoing heart surgery at a hospital in Brockton, Mass., where he lived, his family said. He was 71.

The tone for Mr. Thomas’s long friendship with Brumel was set early on. When Brumel was badly injured in a motorcycle accident in October 1965, a year after the Tokyo Olympics, Mr. Thomas sent him a telegram. “Sometimes a twist of fate seems to have been put there to test a man’s strength of character,” he wrote. “Don’t admit defeat. I sincerely hope you come back to jump again.”

Brumel did compete again but never regained his form. The two men stayed in touch throughout their lives, and Mr. Thomas visited Brumel several times in Moscow. Brumel died in 2003.

John Curtis Thomas was born March 3, 1941, in Boston and grew up in Cambridge, Mass. His father, Curtis, worked as a bus driver; his mother, Ida, was a kitchen employee at Harvard University. He was a star athlete in high school and at Boston University, from which he graduated with a bachelor’s degree in physical and psychological rehabilitation in 1963.

In 1959, while a college freshman, he became the first person to jump 7 feet indoors, sailing over the bar and electrifying a crowd watching the Millrose Games at New York’s Madison Square Garden. Mr. Thomas would win the high jump at the Millrose competition five more times, and officials later named the event in his honor.

Soon after his victory at Millrose, Mr. Thomas injured his left foot in an elevator accident that threatened to end his track and field career. It took him months to recover, but he rebounded and went to the 1960 Rome Olympics. He came in third behind Robert Shavlakadze, who took the gold, and Brumel.

“Losing didn’t bother me,” Mr. Thomas told the New York Times in 1982. “But what did bother me was, a lot of people who were around me suddenly disappeared.”

In 1964, when he won silver in Tokyo, he never mentioned that he had suffered a hernia while training with the U.S. track and field team in California before the Games. He said later that he didn’t want to be sent home or, if he didn’t win, to appear to be making excuses.

He retired from competition at 27 and became a businessman and later a coach and the athletic director at Roxbury Community College in Massachusetts.

In his career, he won four national collegiate titles and seven national AAU championships. He broke the world outdoor record three times, cleared 7 feet 191 times and lost in just eight competitions. He was inducted into the National Track and Field Hall of Fame in 1985.

His marriage to Delores Souza ended in divorce. Survivors include five children; 12 grandchildren; and one great-grandson.

Mr. Thomas spoke of his Olympic experience without bitterness. “It was a good part of my life, and I treat it as part of my life,” he told the Boston Herald in 1994. “I don’t let it encompass my life. I don’t live in the past.”

— Los Angeles Times