Behind on all three cards, Leonard stopped Hearns in the 14th

When Roberto Durán turned his back in New Orleans in November 1980, Sugar Ray Leonard had the WBC welterweight title back. The other half of the division belonged to a 22-year-old from Detroit who had not lost a professional fight.

The Kronk

Thomas Hearns was born in Grand Junction, Tennessee, on 18 October 1958 and moved to Detroit when he was five. He lost three of his first four amateur fights. By the end he was 155–8, and in 1977 he won the national AAU and national Golden Gloves titles at light-welterweight.

His trainer was Emanuel Steward, a former national Golden Gloves bantamweight champion who had started coaching part-time at the Kronk Gym in 1971. The Kronk, on Detroit's far west side, was named after a former city councilman, John F. Kronk, and Steward kept it above 90°F. "There's not as much oxygen in that hot gym," he said, "and I think it's great for conditioning." Steward took a light-hitting amateur and made him one of the most destructive punchers in the sport.

Hearns turned professional in 1977 and knocked out Jerome Hill in two rounds at Olympia Stadium on his debut. He stood 6ft 1in, and they called him the Hitman. Sports Illustrated described it in 1981 as "a nom de guerre he despises but one he seems subconsciously determined to justify". He also went by the Motor City Cobra. In August 1980 he took the WBA welterweight title from Pipino Cuevas in two rounds, then defended it against Luis Primera, Randy Shields and Pablo Baez. He was 32–0, with 30 wins inside the distance.

Leonard goes up, and comes back

Leonard's first defence after New Orleans was against Larry Bonds, a southpaw, at the Carrier Dome in Syracuse in March 1981. He put Bonds down in the fourth and tenth, and the referee stopped it with Bonds taking punishment in a corner.

By the end of that month Leonard and Hearns had agreed to meet in the autumn, but Leonard insisted on fighting Ayub Kalule first. Kalule was 36–0 and had held the WBA light-middleweight title for two years. The promoter Bob Arum said: "I'm somewhat sorry this Leonard-Kalule fight is taking place."

They fought at the Astrodome in Houston on 25 June 1981. After eight hard rounds Leonard hurt Kalule with a right to the head and put him down with a flurry. Kalule got up, and the referee waved it off at 2:59 of the ninth. Leonard was paid $2.5 million. On the same card Hearns stopped Baez in four. Leonard's time at light-middleweight lasted one fight, and he went back down to 147lb.

The Showdown

It was billed as The Showdown: Leonard's WBC and Ring belts against Hearns's WBA title, for the undisputed welterweight championship, over 15 rounds at Caesars Palace in Las Vegas on 16 September 1981. Leonard was 25 and 30–1. He was guaranteed $8 million, Hearns at least $5 million.

Hearns prepared at the Sugar Loaf Resort in northern Michigan. On 3 September, in sparring, he broke the jaw of Marlon Starling with an overhand right, according to Sports Illustrated "while wearing pillow-like 18-ounce gloves". A UPI poll found 34 of 48 writers picking Leonard, and Sports Illustrated's preview said Hearns would find him "too quick and too good".

"Tommy has got the greatest chin I ever trained," Steward said, "and he isn't easy to hit." Hearns said the fight "could put me in the Hall of Fame", then corrected himself: "Well, anyway, it'll make me the top welterweight." Angelo Dundee, in Leonard's corner, had an answer for the size difference. "They talk about Hearns's height and his 78½-inch reach. Ray's is 74 and he'll neutralize the difference with speed."

Caesars Palace

The outdoor arena held a sellout crowd of 23,618, and about 300 million people watched around the world. Leonard came out in a robe with the word "Deliverance" on it. The Washington Post reported that the temperature in the ring was over 100 degrees. The referee was Davey Pearl.

The early rounds went as Hearns wanted. Leonard boxed from a distance, Hearns stalked him, and Leonard struggled with the reach and the jab. By the end of the fifth a swelling was growing under Leonard's left eye and Hearns had a clear lead on the cards.

In the sixth Leonard hurt him, and through the sixth and seventh he gave Hearns a beating. "The sixth should have been the last round," said Janks Morton, Leonard's co-trainer. "Ray had him and he got a little excited."

Hearns recovered and changed the fight. He began to stick and move, and the roles reversed: Leonard became the stalker and Hearns the boxer. Hearns won the ninth, tenth, 11th and 12th on all three cards. Leonard's left eye was closing. "My vision was about a half to a third of normal," he said afterwards. "I couldn't see his right hand coming anymore."

Between the 12th and 13th the words from Leonard's corner were: "You're blowing it now, son."

In the 13th Leonard hurt Hearns with a right hand and followed it with a combination that sent him through the ropes. Hearns got up and was down again before the end of the round. In the 14th Leonard staggered him with an overhand right, pinned him on the ropes and let go another combination. Pearl stopped it at 1:45 of the round, with Hearns still on his feet.

The scorecards at the stoppage read 124–122, 125–122 and 125–121, all for Hearns.

The arguments

"I knew I was ahead," Hearns said. "There was only one problem: I got hit with a good shot. I didn't think the fight should have been stopped." Pearl had no doubts. "I'd stop it again one hundred times in the same circumstance." Nor did Hearns's own trainer. "If he'd made it out of that round he couldn't even have made it back to the corner, much less lasted another round," Steward said. "His legs were gone."

The scoring caused the longer argument. All three judges gave Leonard the sixth and seventh 10–9, and many thought those rounds should have been 10–8. Nevada had only recently adopted the 10-point must system for all fights, and judges had little guidance on whether a round without a knockdown could be scored 10–8. Pat Putnam wrote in Sports Illustrated: "There were only three lopsided rounds, the sixth, seventh and 13th, and Leonard won them all." Pearl put it this way: "I figured Hearns was winning all those light-hitting rounds. But Leonard was doing all the heavy damage."

After the fight the two men met in a half-embrace. "This fight will go down in history," said Steward. "It was a great fight. It had tides and those tides kept turning." Leonard, his left eye almost shut, said: "Until we got in the ring, I didn't realize the sucker was so big." He also said: "I proved that I am the best welterweight in the world." The Ring made it its fight of the year for 1981.

The eye

Leonard fought once more, knocking out Bruce Finch in the third round in February 1982. That spring, training in Buffalo for a defence against Roger Stafford, he complained of blurs and spots in his left eye. Two ophthalmologists there found probable damage to the retina.

On Sunday 9 May 1982 Dr Ronald Michels operated on him at the Wilmer Eye Institute at Johns Hopkins in Baltimore. "His retina, the seeing part of the eye, had become detached," Michels said. "This is serious because it can threaten vision." The Stafford fight, set for Buffalo five days later, was called off. "He wants to get his vision back," said Mike Trainer, Leonard's lawyer. "The last thing on anyone's mind now is whether he will ever throw another punch." Ferdie Pacheco, NBC's boxing consultant, said: "I don't know any boxer who should come back after that."

On 9 November Leonard held "An Evening With Sugar Ray" at the Baltimore Civic Center, where he had made his professional debut in 1977. Howard Cosell was master of ceremonies. Leonard announced his retirement. "I didn't make the decision until tonight," he said. He had lost once in 33 fights, to Durán, whom he had beaten in the rematch, and earned about $40 million.

On the middleweight champion, Marvin Hagler, Leonard said: "It would be one of the greatest fights in boxing history. But that unfortunately won't happen." He added: "There's a lot of people that think I'm going to get back into the ring. I'll prove them wrong."

The other three were still fighting. Durán had been back in the ring since August 1981, and had lost on points to Wilfred Benítez and to Kirkland Laing. Hearns had moved up, and in December 1982, a month after Leonard's announcement, he outpointed Benítez for the WBC light-middleweight title. Hagler had held the middleweight title since Wembley in 1980. Before the Baltimore announcement, Hagler's trainer, Goody Petronelli, had predicted that Leonard would come back for "one more big one".