Sugar Ray Leonard moaned when reminded that, on April 6, it will have been 20 years since his immaculate upset of Marvelous Marvin Hagler in Las Vegas.

Twenty years since he overcame 4-1 odds to capture the undisputed middleweight championship of the world. Twenty years since beating a man considered to be unbeatable.

Twenty years.

“Oh man,” Leonard said, half-amused and half-not, at the revelation. “Yeah, it feels like 20 years. Especially when you bring it up. But I turned 50 back in May, and I know that I had nothing but an illustrious career.”

To call Leonard's career “illustrious” is to call Muhammad Ali “influential.”

In the 1980s, Sugar Ray was the man.

Besides beating Hagler – after nearly three years away from the ring and never previously having fought at middleweight – Leonard claimed victory against a virtual Who's Who of boxing royalty: Thomas Hearns, Roberto Duran, Wilfred Benitez. All, except for Hearns, are in the International Boxing Hall of Fame in Canastota, N.Y. And that's only because the “Hitman” is stubborn and won't officially retire.

Duran will be inducted this summer.

And Leonard, the shy kid from Palmer Park, Md., who was named after Ray Charles, beat them all.

These days, Leonard is helping to prepare Peter Manfredo Jr. for his April challenge of Joe Calzaghe (“I'm not a trainer, per se. What I specialize in is being strategic, tactical, breaking down a guy's strong and weak points”) and overseeing his “Contender” reality series, which will now go international. This season will begin a Ryder Cup-style USA vs. England tournament, perhaps making a popular program more popular.

And maybe making boxing more popular as well, since the show has the ability to penetrate preconceived notions and appeal to the masses.

“I think [the show] is helping boxing out of its slump,” Leonard said. “The fact that it appeals to people, and then they start to like the individual boxers. If they like you, then they follow you. They tune into your fight. And that makes a huge difference with the fans.”

Shooting starts next month, with the new season likely hitting the airwaves in June. The weight class is yet undecided, but Leonard and company are considering the heavyweights.

In Leonard's prime, heavyweights were larger-than-life figures. And boxing was a primetime sport.

“Back in the day, the Olympics were huge on network television,” said the 1976 Olympic gold medalist in the light welterweight division. “Now, it's rare when you see boxing on network TV. And I think that impacts the sport. And there are so many governing bodies. Just too many so-called champions. That dilutes what the championship is all about. One or two belts, that's ok. But when there are five, six, seven, eight, nine 10 belts, it takes away from the game.”

Another problem with today's game? Not enough competitive, evenly-matched fights.

“You don't see champions wanting to fight champions,” Leonard said. “Back in the day, that wasn't true. Champions fought champions. It was put up or shut up.”

And while the fight game itself may pale to what it was in the 1970s and 80s, Leonard admires several fighters from this era. Miguel Cotto. Oscar De La Hoya.

In fact, he thinks De La Hoya will beat pound-for-pound king Floyd Mayweather in their May 5 superfight in Las Vegas – a fight that rekindles memories of Leonard's challenge of Hagler in 1987.

“I feel that Oscar will prevail and beat Floyd Mayweather,” Leonard said. “Oscar knows that this is his last fight, and it could be a defining moment for him. He wants to win the big one before he supposedly steps out of the ring. And he needs this to seal that, to be the man.”

De La Hoya, long considered Leonard's successor in the “Golden Boy” department, has yet to match Sugar Ray's in-the-ring accomplishments. He is often criticized for losing the biggest fights of his career, against Felix Trinidad in 1999, Shane Mosley in 2000 and '03, and Bernard Hopkins in '04.

Which is why Leonard thinks De La Hoya will be the winner come May 5. The Golden Boy will simply want it more.

“Oscar is bigger and taller and stronger, and he's extremely motivated,” he said. “[But] Oscar can't just stand there and pose. He's got to keep it a physical fight and see how he holds up down the stretch. Mayweather can turn his shoulders and block punches, but he won't be as effective against a hard puncher like Oscar. Especially against his left hook. It will be a great fight.”

There are plenty of similarities between Leonard and De La Hoya.

Both won Olympic gold medals. Both turned pro amid much fanfare. And both earned an obscene amount of money – something that, before Leonard, was unprecedented for lighter-weight fighters.

“There was the packaging that we both had, and being able to relate to the public and the media – being accessible,” Leonard said.

So does Leonard think De La Hoya is an all-time great?

“It depends on how you define greatness,” he said. “Are you great because you were bigger than boxing? Or because of ticket sales? Oscar did not win the big ones, even though there was the controversial loss to Trinidad. That was very close. I thought Oscar won, even though he kind of ran the last couple of rounds. I still thought he did enough to win that fight. But that's what boxing is about. What makes the difference between a winner and a loser?”

Like De La Hoya's quest against Mayweather, Leonard fought for boxing history against Hagler.

“The Hagler fight was huge for me; I think it was a matter of defiance, to beat the odds,” he said.

His three most memorable fights are no-brainers: The Hagler victory, the first Hearns win, and the Duran rematch, in which he made “Manos de Piedra” quit and utter the infamous phrase, “No Mas.”

“I didn't get credit for making Duran quit,” Leonard said. “The question became, 'Why did Duran quit?'”

And why did he quit?

“It was frustration,” Leonard said. “Duran was an incredible fighter, a great champion, who had that bully mentality. When I didn't play with him, and fought him back, I think, through frustration and humiliation, he threw his hands up without truly realizing the repercussions it would have on his career.”

Leonard loves Cotto and De La Hoya. But he truly admires fighters from his day –Wilfredo Gomez, Salvador Sanchez and, later, Pernell Whitaker. As a former HBO commentator, he saw many of the great fighters of the 1980s and 90s up close and personal.

If not, he watched on his own.

“Without question, I tuned in – big time,” he said. “I saw Buddy McGirt and Larry Holmes, I go way back. Those were some great memories.”

Recently, another “Sugar” – Shane Mosley – said Leonard is the one fighter in history he'd love to fight.

So how does Leonard think it would go?

“That would be an interesting matchup,” he said with a laugh. “Kind of like a chess match. He has hand speed, no question. That's one of his biggest attributes.”

Leonard thinks today's group of elite fighters – De La Hoya, Mosley, Mayweather, Hopkins, Trinidad – could have competed in his era. Whether they could have won is another story.

“They could compete,” he said. “But, if you were to ask Sugar Ray Robinson about me, or Jake LaMotta about me, they'd say their era was greater. And I feel that way about my era. We all think we fought in the best era in boxing. And I'm sure today's fighters would say the same thing.”

The best fighter Leonard ever saw? The original Sugar Man, Robinson.

“He was a thing of beauty,” Leonard said. “And then there was my man Muhammad Ali. I took a little piece of Ali, of Robinson, of Jersey Joe Walcott, and forged my own style. Watching those guys was beautiful. They transcended the sport, to a whole new level.”