The template was established in that first round. The fighters would stand toe to toe, their heads perilously close. It was southpaw against converted southpaw. Each man was listed at 5 feet 6 inches with a reach of 65 inches. Kim weighed in at 134 1/4, a half-pound lighter than Ray. But more than that, the fighters seemed united in their willingness to give and receive pain.

“I knew I’d have to eat a few,” Ray says.

A furious exchange near the end of the third round — Kim connecting with looping right hooks, then Mancini inflicting a series of body shots — concluded with the Korean pushing Ray back, as if the champion were a little kid. Kim raised his arms and pumped his fists. He had taken Mancini’s best shots.

A lesser fighter, a bully, would have folded right then. Instead, Mancini trudged back to his corner, clearly the more wounded man. The cut man, Paul Percifield, went to work on the left ear, which was split open and spouting blood. Less easily treated was Ray’s left hand. After throwing a left hook that bounced off the top of Duk-koo’s head, it was swollen and throbbing with pain.

The longer it went, this accrual of stubborn brutalities, the more it seemed a homage to Mancini’s father, the original Boom Boom. Waiting on the bell for the sixth, Gil Clancy felt uneasy. Clancy, one of two CBS analysts, had been in the corner March 24, 1962, at Madison Square Garden, when his fighter, the welterweight Emile Griffith, beat Benny “Kid” Paret into a fatal coma. Now the former trainer spoke in an ominous aside to his fellow broadcasters, Tim Ryan and Ray Leonard. “Something’s going to happen in this fight,” Clancy said quietly. “Either one guy’s gonna get busted up, or nail the other guy very badly.”

The fight settled into a rhythm. Ray would win the first part of a round, then, when it seemed against all probability, Duk-koo would answer with shots to the belly and straight lefts, one of which, at the end of the eighth, snapped back Ray’s head. They would breathe and bleed and lean on each other, achieving a state of violent intimacy that, looking back, seems almost fraternal.

“I knew him better than his mother,” Ray says.

By the 11th, it seemed as if each fighter was wearing a sickly bluish mask. Finally, in the 12th, Ray shot an uppercut to the heart that caused Duk-koo’s left knee to touch the canvas. It might have been ruled a knockdown if Duk-koo had not regained his footing so quickly. By now, he was clearly the more fatigued fighter, as tired as he was suddenly admired. Fans rose in appreciation after the 12th.

The next round began with Ray delivering 44 consecutive punches, an onslaught that slowed only when Duk-koo found enough of his opponent to grab. Then, after breaking free of that grasp, Ray got off 17 more, most of them hooks to the body. Seventy-nine seconds of the 13th round would elapse before Duk-koo threw his first punch.