Sugar Ray Leonard on first Thomas Hearns fight: 'What the hell is going on here?'

Flashback: Sugar Ray's still got blazing fast hands at 62 (0:15)

Boxing legend Sugar Ray Leonard shares a training video on social media showing off his speed at 62 years old. (0:15)

Over the course of boxing history, only a handful of special fighters are involved in an event that transcends the sport. Sugar Ray Leonard fought 40 professional bouts, with memorable encounters against Robert Duran, Marvin Hagler, Wilfred Benitez and Hector "Macho" Camacho, among many others.

But there was perhaps no greater achievement than his showdown against an undefeated Thomas Hearns on Sept. 16, 1981.

At the time, Hearns was 32-0 and the reigning WBA 147-pound titlist. Leonard was the defending WBC champion. They clashed at Caesars Palace in Las Vegas for the undisputed welterweight crown. It was a matchup of two of the very best boxers in the world -- each with sizable followings -- and both in their physical prime.

Leonard was the pure boxer, with "The Hitman" Hearns -- utilizing his vaunted right hand -- being the puncher.

The fight ultimately didn't fit into that linear structure, and instead unfolded like a great novel. The early chapters were dominated by the boxing of the tall and angular Hearns, who kept Leonard at bay with his rapier jab.

"That jab is a thing of beauty -- it's not just fast, it's hard too," said Leonard, who claims that punch was much more of a factor than Hearns' power shots.

"It was miraculous the way he boxed. I said, 'this guy's moving around laterally, inside, outside, up and down jabbing, I couldn't get him," said Leonard, who for the first several rounds was stuck on the outer perimeter of the ring, not able to create much offense. "Tommy was a freak of nature, and when he showed his boxing ability, that blew my mind. I was like, 'What the hell is going on here?'"

Early on, Hearns was piling up the rounds by controlling the distance and the spacing in the ring. After five frames, he was on top by the scores of 49-46 on two cards, and 50-45 on the other.

Leonard knew he had fallen behind on the cards. "Fighters know when they're losing, we know that, trust me. They know, they won't tell you, but they know. We know."

Yet with one left hook that stunned Hearns in the sixth round, Leonard was able to capture the momentum and the physical control of the bout. Leonard could also punch with power, and for the first time in his career, Hearns was staggered. Leonard hurt his rival a few more times in the next few rounds, keyed by his lethal left hook and dazzling combinations. Somehow, Hearns survived the mid-rounds onslaught.

"What the fans got to understand is: It was hot as hell in that ring," said Leonard, pointing out that this event was staged outdoors in the searing desert heat of Vegas, with temperatures that climbed into the mid-90s. "It was hot, and that pace. But then again, when I'd hit him and rock him, I became rejuvenated. I had that thing, that intestinal fortitude, that thing a lot of fighters have -- we all have it, but they can't activate it.

From Rounds 6 through 9, Leonard was in charge, but it came at a price.

"I said, 'Who the hell taught him this? What the hell?" says Leonard. "He's not known for that. And he started moving and dancing, and I'm like, 'whoa, man,' but I kept a poker face." Sugar Ray Leonard

"I wish I could really articulate just how tired, how exhausted I was -- and he was too," Leonard said. "It became a fast pace, the tempo, we were throwing shots and we were throwing combinations."

Going into the 10th round, Leonard had closed the gap on the scorecards, but Hearns was still leading 87-84 on two judges' tallies and 86-85 on the third.

But that's when Hearns found another gear and his legs returned, rendering Leonard ineffective at the end of his jab.

"I said, 'Who the hell taught him this? What the hell?" Leonard said. "He's not known for that. And he started moving and dancing, and I'm like, 'whoa, man,' but I kept a poker face."

Leonard's visibly swollen left eye was becoming increasingly more of a slit at the end of Round 11, the result of taking so many of Hearns' sharp jabs. What was a relatively minor inconvenience in the early stages was now a major issue in the championship rounds.

After winning the 12th, Hearns held a commanding lead on all three cards (116-112, 117-111 and 117-112) and as Leonard sat down on his stool, lead cornerman Angelo Dundee uttered perhaps the most memorable words ever given to a boxer in the heat of battle.

"You've got nine minutes. You're blowing it, now, son. You're blowing it. ... Ray, we gotta separate the men from the boys, we're blowing it ... We gotta take it away from him."

"That was the perfect sound bite," Leonard said of that iconic moment. "He said it at the right time, and that statement he said, it was to the point, no bulls---, and he was calm and he was composed."

For Leonard, it wasn't just what Dundee said, but how he said it. Stern, yet measured and calm, delivered with the proper sense of urgency, but no panic.

Leonard found that last reservoir of energy to turn things around. A straight right halfway through the 13th round staggered Hearns, who began to wilt as Leonard started to hit him with a barrage of punches that were as hard as they were fast. After getting pushed through the ropes and getting a slight respite, Hearns would be hammered continuously until he sagged into the ropes late in the round, where he was given the mandatory eight count by referee Davey Pearl.

An overhand right in the 14th round buzzed Hearns, who at that point was in full retreat and in survival mode. Leonard, who had the well-earned reputation as being boxing's greatest finisher, applied more heat as he hurled punches to Hearns with malice. Beyond the balletic grace that he had as a prizefighter, there was a certain savagery to his attack. It gave Pearl no other choice but to wave off the fight with just over a minute left in the round.

Leonard-Hearns I was much more than just a fight, but something that has become a part of boxing lore. It was a bout that has been made into documentaries and written about in books. This event took place back when boxing mattered more to the public at large. But to those who still love boxing, perhaps it matters even more now.

He doesn't call it his best victory, as Leonard has a keen appreciation for his other landmark wins, but in the past he has called it his most "important" fight, and it's one that he watches often.

"It's such a regular thing," Leonard said. "I do motivational speaking and I show clips of my fights, what it takes to be a winner, this and that. I tell you, I'm now 64 years old, man. It's crazy because there's more appreciation for those fights."