LAS VEGAS -- Top Rank promoter Bob Arum likes to joke that Manny Pacquiao is so good that maybe someday he could challenge heavyweight champion Wladimir Klitschko.
Arum is obviously kidding, but his point is well taken.
Pacquiao continued to defy boxing logic by once again moving up in weight and turning in another dominant, title-winning performance on Saturday night at the Mandalay Bay Events Center, this time claiming a lightweight championship.
And for those who didn't already have Pacquiao No. 1 on the pound-for-pound list, perhaps favoring Joe Calzaghe like ESPN.com has since Floyd Mayweather's retirement earlier this month, get ready for another change of the guard.
Pacquiao is the new king.
His victim this time was big-hearted, but skill-deprived David Diaz, who showed huge heart but had no answers for Pacquiao's swarming style, much to the delight of the 8,362 mostly Filipinos who filled the arena to cheer their favorite son.
It was all Pacquiao, from the opening round until he finally knocked Diaz face-first to the mat with a left to the jaw at 2:23 of the ninth round.
Diaz was so thoroughly beaten that referee Vic Drakulich didn't even bother to count.
Diaz had been cut severely over his right eye in the fourth round.
His left eye was a purple, swollen mass.
His face was a bloody mess.
And Pacquiao, who by the mid-rounds looked like a boy pulling the wings off a fly with the way he was tormenting Diaz, did not have a mark on him. He looked like he could fight again next week.
The victory put Pacquiao into the historic elite as he claimed a title in his fifth weight division. Pacquiao, who began his professional career at 106 pounds, has won titles at flyweight (112), junior featherweight (122), featherweight (126, by virtue of his knockout of lineal champion but sanctioning belt-free Marco Antonio Barrera) and, in March, he outpointed Juan Manuel Marquez for the junior lightweight title (130).
It was up the scale again to challenge Diaz, the overachieving 32-year-old from Chicago and former Olympian who made his best payday, $850,000. But Diaz paid for it the entire fight.
It begs the question: Just how high can Pacquiao, 29, keep moving up the scale and maintain his brutal effectiveness?
At 135 pounds, Pacquiao looked strong, fast and sharp. He's going to be a handful for anyone in the deep division, and that includes recognized champion Joel Casamayor, unified titleholder Nate Campbell, Marquez (who is moving up to fight Casamayor in September) and former titleholder Juan Diaz.
David Diaz (34-2-1, 17 KOs), for one, is a believer.
"Manny was too fast," he said.
Understatement do you think?
"I could deal with the power but not his speed," Diaz said. "I got tricked by his speed. I gave it my all. His speed is what it sealed it for me. His speed was uncontrollable."
"[The cut] didn't bother me," he said. "But I thought he had a knife. It's like he was hitting me with a blade. I thought [Pacquiao trainer Freddie Roach] was in there hitting me too. What can I say? I lost today, I'll win tomorrow. To go like that with a guy like Manny Pacquiao, I think I'm doing pretty good."
Pacquiao (47-3-2, 35 KOs) was clearly at the top of his game against an outgunned opponent.
You can see his pure dominance again when HBO replays the bout on Thursday (9:30 p.m. ET/PT) and again on Saturday (10 p.m. ET/PT).
"I feel much stronger and more powerful at 135," Pacquiao said. "This is where I plan to stay."
That should be scary for the rest of the division. But Pacquiao also brings the golden ticket to the division. He earned at least $3 million and is by far the most bankable attraction in the division.
Whomever gets the next crack at him -- possibly junior lightweight beltholder Edwin Valero moving up in weight on Nov. 8 -- will probably make a career-best purse.
"Diaz caught a lot of punches," Pacquiao said. "I'm surprised he didn't go down earlier. It's hard to fight a southpaw, but I jabbed, jabbed to set him up for the knockout. I can fight in November. Who I fight is the job of my promoter."
Pacquiao likely will defend his new belt in the fall. But beyond that there is talk of his moving up yet again to the 140-pound junior welterweight division, where Ricky Hatton reigns as king.
Hatton, of course, faces titleholder Paulie Malignaggi in November. But after that, a fight with Pacquiao could happen in the first part of 2009.
So how will Pacquiao fare?
"I would think that Manny can fight at 140," Arum said. "But I think going past 140 would be a mistake. Every time I think of Manny in a ring with [welterweights] Miguel Cotto or Antonio Margarito it begins to look a little ludicrous. Hatton would be OK. He could probably fight a Hatton or [Ricardo] Torres or [Kendall] Holt. He'd be all right there. I wouldn't make him a favorite, but he'd be OK. But going past 140 would be a big problem. Hatton would be a legitimate fight."
Roach agrees with Arum.
"I would say the right 140-pounder would be OK," Roach said. "I wouldn't take all of them. Ricky Hatton is not a big guy. He's about the same height as Pacquiao, maybe an inch taller. And he's one guy I would let Manny fight at 140. But not the giants."
But what about the often-discussed possibility of a move to welterweight (147) to fight Oscar De La Hoya?
Although it's a long shot, the possibility of the fight has been tossed around, and Roach said they'd be interested.
"Then they talk about De La Hoya," he said. "If De La Hoya said he wants to fight, we'd fight him at 147 because it's the right guy at 147 because he's older. He's not the same guy that he was when he was younger. With the right money, we'd take that fight, yes. You're probably supposed to lose that fight, but I don't think he loses though. I know Oscar pretty well. I like Oscar, I have nothing against him, but it would be a good fight."
Isn't every Pacquiao fight?
Dan Rafael is the boxing writer for ESPN.com.