Mayweather might edge it, says de la Hoya
Pacquiao has to keep attacking to win 'Fight of the Century', says de la Hoya
He retired in 2009, 45 fights old, with 30 knockouts and six losses.
Oscar de la Hoya is one of the greatest boxers in history, an electrifying athlete with the movie star looks and the moniker to go with it.
He was the "Golden Boy", who dazzled in the 1990s and for much of the following decade, with his fights grossing about US$700 million ($958m) in all.
The Mexican-American, who ruled at weight classes ranging from lightweight, welterweight to middleweight, is well-placed to talk about the highly anticipated fight between Floyd Mayweather Jr and Manny Pacquiao on Sunday morning (Singapore time).
He hit them both in two punishing fights, and was hurt by both in two losing encounters.
Like so many others, de la Hoya expects a close contest, and he knows whose punch can pack a knockout blow.
Speaking to The New Paper at the Icons Cup golf tournament in Dubai last week, the 42-year-old said: "I like Manny's fighting spirit; he's the people's champion and the whole world wants him to win.
"Both fighters have the tools to win this bout, and I think it will go the full 12 rounds.
"I won't be surprised if there is a knockout though, and if there is, it will be Manny who gets the K.O.
"Mayweather just doesn't have the power. If Manny catches him, it's over.
"Manny can't slow down a fraction. He has to press the action on Mayweather. Otherwise, Mayweather might just nick it in the end."
De la Hoya recognised his time was up after a nail-biting split decision defeat by Mayweather in 2007 in one of the biggest fights of all time.
A little over 18 months later, he did not come out for the ninth round and Pacquiao won on a technical K.O.
One would not be wrong to suggest de la Hoya launched Mayweather and Pacquiao into superstardom.
Mayweather is brash, surrounds himself with glitzy paraphernalia and scantily clad women and unashamedly boasts he fights for the money.
Pacquiao says he was a sinner who has rediscovered his faith and is now a man of God.
RAGS TO RICHES
The 36-year-old was dirt poor as a child who had to survive on the streets in the Philippines, and is now the only eight-division world champion, and a congressman who hopes to one day be President of his country.
Mayweather is not even liked in America, protected by bodyguards he wooed from rap star Snoop Dogg, flying around in a private jet and hosting parties with cash strewn everywhere.
It is easy to understand why de la Hoya is a fan of Pacquiao, but his head tells him that Mayweather will win.
"Mayweather is quick, extremely smart, and he knows how to win matches without knocking out his opponent," de la Hoya said.
"Manny will throw a thousand punches, but he hasn't knocked out someone in a while... if this fight was a couple of years ago, I'd tip the scale to Manny."
The fight has been billed as the richest in history.
Mayweather, who boasts an unbeaten 47-0 record with 26 knockouts, will earn at least US$150 million. Pacquiao, with a record of 57 wins, five losses and two draws with 38 knockouts, will collect US$80 million or more.
Broadcast "live" around the world, the excitement and interest surrounding this fight harks back to the days when Ali, Frazier and Foreman roamed the earth, middleweights like Leonard, Hearns, Hagler and Duran fought vicious contests, and Tyson stalked so menacingly.
This is must-see TV, with the advantage in Mayweather's corner.
Aside from fighting on home soil, de la Hoya believes the American has the edge because of referee Kenny Bayless.
Said de la Hoya: "When I heard Kenny Bayless was going to be the referee, I said, 'That's one point for Mayweather right there'."
According to de la Hoya, Bayless has always been quick to protect his countryman, whenever he officiates his bouts.
But de la Hoya is not completely without hope. He said: "The close rounds will go to Mayweather. But, if Manny can get ahead early, it will be an interesting fight."