LAS VEGAS?Speed, indeed, kills.

David Diaz acknowledged this on Saturday after he was knocked out by the speedy, rapid-punching Manny Pacquiao and yielded his World Boxing Council lightweight crown to the Filipino ring icon.

?It was all speed,? said Diaz, during the post-fight interview. ?He boxed more than I thought he would box. No excuses.?

After regaining his bearings on the ring, the 32-year-old Diaz admitted he never saw the killer punch?prefaced by a head-snapping jab?coming.

?I think it was the left hand,? Diaz said. ?He was f****ng fast. I didn?t see [the left hand] coming.?

The ever-gracious Diaz was down on the floor for more than a minute and had to be seated on a stool after Pacquiao caught him with a left hook in the ninth round.

?He?s a clean fighter.?

And, as Diaz himself admitted, a really good one.

?I was taking his punches and I said ?hey, he doesn?t hit that hard? and all of a sudden I?m on the floor and [wondering] ?what the heck happened???

Perhaps Diaz didn?t even know that a worried Pacquiao tugged on his arms to help him up after referee Vic Drakulich declared the fight over with 2:24 gone in the round.

Pacquiao?s performance validated trainer Freddie Roach?s faith in the Filipino ring icon. Roach said in pre-fight interviews that he was certain Pacquiao would knock Diaz out.

?I knew that it (fight) would last long because Diaz is so durable,? said Roach, a multi-awarded trainer. ?But sooner or later, I knew Manny?s punches would break him down.?

Diaz, however, said the devastating loss won?t make him a quitter.

?I had great fun,? said Diaz, who had a mouse on his left eye and cuts on the right eyebrow and the bridge of his nose.

In a show of class, instead of proceeding directly to the Valley Hospital where he will be stitched up, Diaz opted to appear before the media.

The 32-year-old Diaz even thanked the Filipinos for their fair treatment of him during the fight?s promotional tours in the United States.

?The only thing about Manny is he hit me a little more than I hit him,? joked Diaz, who was accompanied by wife Tanya and close friends.