John Devitt, an Australian champion swimmer who was awarded a gold medal in the showcase race of the 1960 Rome Olympics even though he had a slower time than the runner-up, died on Thursday in Sydney. He was 86.

The Australian Olympic Committee announced the death, saying it came after a long illness.

Devitt was one of Australia’s greatest swimmers, thrilling the home crowds when he won gold and silver medals in the 1956 Olympics in Melbourne. He went on to win a bronze medal as well in the 1960 Games. Including relays, he broke 14 world records and won 13 Australian championships.

But beyond Australia he may be best remembered for his part in the finish of the 100-meter freestyle final in Rome, one of the more freakish moments in sports history. It led to an overhaul of the way the placings and times for Swimming races were decided, with electronic timers and photos replacing judgment calls.

Devitt, at 23 and a lean 6-foot-1 in 1960, was captain of the Australian men’s swimming team for the second consecutive Olympics and the race favorite. One opponent was Lance Larson of Monterey Park, Calif., a 20-year-old sophomore at the University of Southern California.

In the eight-man final, Devitt was clearly ahead until the last 20 meters, when Larson, in an adjoining lane, caught up to him. They touched the finish wall almost together, with Larson seemingly slightly ahead. Each congratulated the other, and they then both waited for the official results. The wait was excruciating — almost 10 minutes.

In that era, the rules called for three judges to choose first place, three other judges to choose second, and three others to choose third. Each lane had three timekeepers, but their timing, by hand, was almost incidental in determining who finished where. There was no starting beep or automatic touch pads or accepted electronic timing or replays, as there are in major swimming competitions today.

When the judges were polled after the race, the results were unusual. Two of the three first-place judges had picked Devitt as the winner, and one had picked Larson. Two of the second-place judges had picked Devitt for second, and one had picked Larson. The three timekeepers for Devitt’s lane had all timed him in 55.2 seconds. The three in Larson’s lane had timed the American in 55.0, 55.1 and 55.1.

And a newly introduced automatic timing machine — which was started electronically but stopped manually, and which was to be consulted only when judges were tied, as they were in Rome — had Larson in 55.10 seconds and Devitt in 55.16.

It seemed obvious that Larson had won — until the chief judge, Hans Runstromer of Germany, interceded and voted for Devitt.

American officials protested the decision to the jury of appeals, saying the rules did not give the chief judge a vote. Runstromer disagreed. Besides, he said, he had been standing on the finish line and had seen the whole thing. A Sports Illustrated photograph, however, showed that he was 25 yards away at the time and had viewed the finish at an angle.

The appeal failed. The Americans appealed three times more in the next four years and lost every time. As Larson said, “It was a bad deal.”

Devitt disagreed, saying that some of the judges and timers might have missed his touch because it came after a short stroke underwater.

In the end, as The New York Herald Tribune wrote after the race, “This required a Solomon, and the International Swimming Federation was fresh out of Solomons.”

In 2009, a paper in the journal Physical Culture and Sport: Studies and Research concluded that “Runstromer’s decision undoubtedly sanctioned untruth.”

In other words, the study said, Larson had won.

Since the 1968 Olympics in Mexico City, all international swim races have been timed electronically.

John Thomas Devitt was born on Feb. 4, 1937, in Granville, a suburb of Sydney. He started swimming at age 4 and often trained by swimming against currents of discharged water from a power plant.

Devitt’s gold medal in Melbourne in 1956 came in the 4×200-meter relay; he won the silver there in the 100-meter freestyle. Besides the gold medal in Rome, he took the bronze there in the 4×200-meter freestyle.

He retired after the 1960 Olympics and was elected to the International Swimming Hall of Fame in 1979. (Larson was elected in 1980.)

His survivors include his wife, Wendy, whom he married in 1961.

In later years, Devitt was the European manager for the Speedo swimwear company and opened his own swimming equipment company. He headed the Australian swimming federation, served as a high official of the Australian Olympic Committee and helped bring the 2000 Olympics to Sydney.

In the 1980s, Devitt and Larson met for the first time since their race, and all was pleasant. But Larson never forgot those Olympics. “I think,” he said, “John has had to live with the feeling for many years that he probably didn’t really win that gold medal.”

Frank Litsky, a longtime sportswriter for The Times, died in 2018. William McDonald contributed reporting.