LAS VEGAS — Although Juan Manuel Marquez’s right eye was swollen nearly shut, he kept it focused on his one remaining goal — a third fight with Manny Pacquiao.

Marquez didn’t exactly make himself more attractive to boxing’s pound-for-pound champion with his systematic dismantling of Juan Diaz.

Marquez unanimously outpointed Diaz on Saturday night, picking apart his younger opponent to retain the WBA and WBO lightweight titles.

Marquez captivated the crowd at the Mandalay Bay Events Center with precise punching and slick defense in a rematch that was nearly as entertaining as the fighters’ thrilling first meeting, which Marquez won on a ninth-round stoppage in February 2009.

Marquez (51-5-1, 37 KOs), who turns 37 next month, further erased memories of his one-sided loss to the larger Floyd Mayweather Jr. last September by dominating another opponent closer to his own size.

“The first one was difficult, and so was this one,” Marquez said. “He’s a very good boxer. Like every true Mexican warrior, we both fought with all of our hearts and left it all in the ring.”

Marquez reiterated his call for a third fight with Pacquiao, believing he’s the only fighter outside of Mayweather who can worry the Filipino congressman. Their first two meetings resulted in a draw in 2004 and a split-decision loss for Marquez in 2008.

“It’s good for all fight fans,” Marquez said. “The Mexicans, the Filipinos, everyone wants to see it. That’s the most important fight to me now. I’ll be ready for November, and hopefully Pacquiao will take the fight.”

But Pacquiao is in negotiations to fight Antonio Margarito on Nov. 13. Both of those fighters are represented by Top Rank, while Marquez is backed by Golden Boy — and the two companies have been increasingly unwilling to match their fighters against each other in recent years.

Diaz (35-4) has lost four of his last six fights, yet showed remarkable stamina and courage against one of boxing’s most punishing fighters. The University of Houston graduate and aspiring lawyer was sharp again — just not sharp enough to beat arguably the most accomplished Mexican fighter of his generation.

“I fought the best fight I could,” Diaz said. “We were trading punches. We fought in, we fought out. I didn’t stand in front of him. I wanted to get in there and then get out, but it was hard, and I got hit with a couple of good shots. … I did the best I could. I followed the game plan, worked off my jab, but he’s a great fighter. He was the better man.”

Judge Jerry Roth favored Marquez 116-112, while Glenn Trowbridge scored it 118-110 and Patricia Morse Jarman had it 117-111. The Associated Press scored 10 rounds for Marquez, 118-110.

Marquez landed 288 punches to Diaz’s 155, outlanding Diaz in every round, according to CompuBox’s statistics. Marquez connected with nearly 50 percent of his power punches, landing 168 to Diaz’s 74.

Marquez’s performance burnished a career that now likely surpasses the achievements of Marco Antonio Barrera and Erik Morales, the other two contenders for Mexican pre-eminence. Marquez is a three-division world champion who could be a significant factor when he moves up to 140 pounds in the coming years, another major player in a loaded weight class — yet Pacquiao looms over everything Marquez does.

Marquez’s back-and-forth victory over Diaz was widely considered the best fight of last year. The rematch again was an entertaining contest between two fighters with perfectly meshing styles: the hard-charging “Baby Bull” Diaz against Marquez, the crafty, counterpunching Mexican star.

The second and third rounds of the rematch were close, with Diaz landing enough flurries to keep Marquez on the defensive. But Marquez gradually took control of the fight, peppering Diaz with left hooks and right hands while barely staying out of trouble.

The middle rounds had a brutal similarity, with Marquez chopping through Diaz’s attack. Although swelling developed around Marquez’s right eye, it didn’t seem to bother him at all — and Diaz began bleeding from a cut inside his mouth.

The 12th round was wide open, with the fighters abandoning defense and trading shots to the bell. Marquez leaped on the ropes to celebrate another victory.

The Las Vegas crowd firmly backed Marquez, the Mexico City native from a fighting family that includes his brother, Rafael, who will fight Juan Manuel Lopez in Vegas on Sept. 18 in an attempt to become the first boxing brothers to hold three division titles apiece.

Diaz has his college degree and far more post-ring career opportunities than most fighters. He is eager to pursue a career in law and perhaps politics, but didn’t end his boxing career immediately afterward.

“I don’t know what I’m going to do,” Diaz said. “I’m going to consider all the facts. I’m going to take the LSAT, and that’s another fact. I’ve been fighting for 10 years, longer than a lot of fighters, so I’m just going to have to figure it out.”

On the stacked undercard, unheralded Russian middleweight Dmitry Pirog stopped Daniel Jacobs with a crushing overhand right to win the vacant WBO title. Robert Guerrero comfortably outpointed Cuban veteran Joel Casamayor, and Jorge Linares easily beat Rocky Juarez.