LAS VEGAS — The WBC lightweight title belt looked perfectly natural hanging off Manny Pacquiao's shoulder after he battered David Diaz.

That invisible crown on his head seemed like a perfect fit as well.

From the first too-quick combination to the decisive left cross to the jaw, Pacquiao's ninth-round TKO victory at the Mandalay Bay Events Center also seemed to be a coronation. Most observers left the fight convinced the Filipino star deserves the unofficial honor of being known as the best pound-for-pound boxer in the world, even if Pacquiao himself still doesn't care about that particular title.

"It is not for me to say," Pacquiao said. "I just want the fans to be happy with me."

With a championship belt in his fourth weight class and a landmark victory in his fifth division, Pacquiao showed he's only getting better as he gets bigger. The next few years will determine just how big he can get as he embarks on what's sure to be an eventful tour of the talented lightweight division — with perhaps an incredibly lucrative side trip to junior welterweight for a fight against Ricky Hatton.

Pacquiao's dominant victory over Diaz answered several questions about the Filipino star's size and focus. In his first fight as a lightweight, Pacquiao was as quick and powerful as ever — yet he also stayed disciplined, picking apart Diaz with a precision that hasn't always been shown by a fighter who loves a good brawl.

"The game plan stayed intact, and he fought a great fight," trainer Freddie Roach said. "David Diaz, he's a tough guy, but being a tough guy isn't enough. ... I've never given an A-plus before, but he fought a great fight. There's not a lot he could have done better."

Before Diaz went to a hospital for a plastic surgeon's attention on his cuts, the likable but overmatched champion put some perspective on the confounding experience of fighting the fastest man he had ever seen in the ring.

"Cuts didn't bother me at all," said Diaz, who bled profusely from his swollen left eye and at least two additional spots on his face before Pacquiao finished it. "I could deal with the power, but not his speed. I got tricked by his speed. I gave it my all. His speed is what it sealed it for me. His speed was uncontrollable."

Diaz made $850,000 in his biggest payday, but will drop back down into the second tier of lightweights while Pacquiao, who made $3 million, decides which 135-pounder to trouble next.

With more fans and better television drawing power than any other lightweight, Pacquiao is the new target for the rest of a deep division that includes three-belt champion Nate Campbell, linear champ Joel Casamayor, former three-belt king Juan Diaz, Australian brawler Michael Katsidis and Juan Manuel Marquez, who's moving up to 135 pounds to fight Casamayor in September.

Since most of the top lightweights already are scheduled to fight each other this fall, Pacquiao's next fight on Nov. 8 is expected to be a title defense against Edwin Valero, the unbeaten (24-0, 24 KOs) Venezuelan who isn't currently allowed to fight in Nevada because of a medical suspension stemming from a 2001 motorcycle accident. That fight probably would be in Texas if Top Rank promoter Bob Arum can't persuade Las Vegas officials to approve him.

Another move up for Pacquiao also seems likely soon, since the money that could be made from a fight against 140-pound king Hatton is too good to ignore. Hatton, the English brawler who got knocked out by Floyd Mayweather Jr. last December, is scheduled to fight Paulie Malignaggi in November.

Pacquiao and Marquez also are still expected to fight a third time. Roach thinks their first two meetings — a 2004 draw and a tremendously entertaining split-decision victory for Pacquiao last March — might turn out to be more competitive fights than the third match, as long as Pacquiao remains the boxer he was against Diaz.

"If Manny fights Marquez like that, on his toes and boxes, he'll demolish him," Roach said. "We moved into Marquez's power shots all night long. Tonight we moved away from David's power, and he couldn't do anything."

HBO will replay the Diaz-Pacquiao fight on Thursday and Saturday.