Even now, with more than six years of hindsight,
Shaking his head recently at the bold move he made on Dec. 6, 2008, just before his 30th birthday, Pacquiao ranks his dominating upset of the "Golden Boy" as his greatest fight yet.
The bout was dreamed up by HBO boxing analyst Larry Merchant, a super-fight that would match the six-division champion De La Hoya, in what would be his final fight before retirement, against the rising star Pacquiao.
There was some deep bitterness attached to the match.
De La Hoya and the then-CEO of his boxing promotion company, Richard Schaefer, were in fierce competition with Pacquiao's promoter Bob Arum.
One watershed incident in the rivalry came earlier when De La Hoya and Schaefer met with Pacquiao at a Los Angeles steakhouse with a briefcase loaded with cash, urging him to join Golden Boy Promotions.
He didn't, and Arum wanted it known which promoter knew boxing best, and which was "a Swiss banker," as Arum would dismiss Schaefer as.
So Arum agreed to the fight. Even if Pacquiao would have to move up in weight, he was blessed with the speed and talent at the peak of his career and De La Hoya would be forced to make 147 pounds after fighting at middleweight (160) four years earlier and not making the welterweight limit since 2001.
Age was also an issue. While De La Hoya was clearly throwing the heavier blows in training camp, he admitted in Big Bear his "best friend" had become ice to soothe the aches of his workouts.
At the weigh-in, a dry-looking De La Hoya weighed 145 pounds.
Pacquiao weighed 142 for his first fight above 135 pounds, and told The Times after stepping off the scale: "Speed will be the key to this fight. We decided early in training that speed is the most important factor and that's why I came in at this weight."
Pacquiao trainer Freddie Roach watched De La Hoya fight months earlier in Carson and told Arum to make the fight, that De La Hoya "couldn't pull the trigger" any longer. From the opening bell, Pacquiao's reaction time ruled.
"I knew right away in the first round that I had him," Pacquiao said after evading De La Hoya's best weapon, the jab.
Here's how Round 3 was described: "Pacquiao pumped in jab after jab to Oscar's face. Just as he worked on in training, he was masterful at ducking under Oscar's left and swinging for the body. Oscar's punches were wide, easy-to-avoid efforts, and a bump of swelling emerged at his left eyebrow."
Someone ringside said Pacquiao was "teeing off like batting practice." In the fifth, De La Hoya nodded to Pacquiao with a beaten expression on his face.
In Round 7, CompuBox recorded a staggering 45 power punches by Pacquiao. That's the most power punches De La Hoya ever absorbed in 31 fights monitored by the punch stat company. Pacquiao swarmed with a barrage of blows in De La Hoya's corner, referee Tony Weeks looking on closely, then did it again across the ring.
The final round of De La Hoya's career was described like this:
"Pacquiao again corners De La Hoya with a sharp combination. De La Hoya's attempted jab was in vain. De La Hoya is clearly drained, and worse, he's wounded by a big Pacquiao left. A De La Hoya combination elicits a taunt from Pacquiao, who raises his arms, urging on the ex-champ and unleashing a final flurry at the end of the round. The blood under Oscar's left eye is flowing freely."
Repeatedly, in De La Hoya's corner after the round, he was asked if he wanted the fight stopped. No response came, maybe the slightest head nod.
That was enough for trainer "Nacho" Beristain, who declared the fight over, with ring announcer Michael Buffer handling the landmark event with dignity.
"Tonight, we turn a page in boxing history."
The Times' headline for the bout was, "Pacquiao Never Quits, So De La Hoya Has To."