Losers go home unnoticed. David Diaz was not a loser last Saturday night.

The lightweight title was taken from him by perhaps the most talented fighter in the world, but that did not make Diaz a loser. It meant he lost a fight, which is not the same thing.

Over nine rugged and bloody rounds, Diaz was a profile in courage painted mostly in red. He was a champion who lost his title, and a lot of blood in the process, but who never lost heart. Forgotten in the well deserved praise heaped upon Manny Pacquiao for his dominating performance in knocking Diaz out to win his fourth world title in decidedly one-sided fashion was that Diaz was the blood-encrusted vision of what it means to be a fighter.

He did not win at the Mandalay Bay Events Center because God blessed Pacquiao with far more gifts than he showered upon the Chicago-born former Olympian but he did not lose because of any internal failings. Manny Pacquiao had many things Diaz did not last Saturday night but he didn’t have more heart. That would simply not have been possible.

Pacquiao’s hand speed advantage was clear and devastating. It was something for which Diaz could find no antidote.

The perfectly placed left hook that knocked Diaz onto his face in the center of the ring in the ninth round was thrown as if by someone giving a clinic on the art of boxing. It was perfection, a punch that went barely half a foot and landed, unseen, with concussive effect.

Pacquiao’s footwork and boxing skills, which are both often underrated only because his punching power and aggressiveness are so fearsome, were obvious from the first round to the fight’s thunderous close.

Lost in all of Pacquiao’s dominance was the bravery of Diaz, whose face looked like someone had thrown a bucket of plasma on it after barely four rounds were completed. By then the bridge of Diaz’s nose had been split apart, his scalp had a cut that turned his hair and right ear red and a long and widening split had opened over about half the length of his right eye lid. The latter would bleed profusely for the rest of the night; trainer and cut man Jim Strickland never able to staunch the flow of Diaz’s blood into his eye and down along his face.

The hopelessness of Diaz’s situation was apparent after barely six minutes of boxing. Pacquiao was beating him to the punch repeatedly and throwing in so many quick flurries that Diaz found it all but impossible to wade through those punches and get inside, the one place where he might have been safe. Safe, actually, is too strong a word, but he would have at least been in the eye of a storm of leather that was buffeting him like February winds in his native Chicago might on a snowy night.

By late in the fourth round the referee had already stopped the action once to have the cut over Diaz’s eye examined by a ringside physician. Being a brave doctor, he said Diaz was fine, which he wasn’t, and let the fight continue. About a minute later Pacquiao drilled Diaz with the kind of startlingly hard punch that either sends you down or leads you to do what Diaz did, which was to shake his head “No!’’ to let the crowd know that punch did not affect him.

Between rounds Strickland pressed a Q-tip soaked in coagulant as well as about half his finger into the red valley Pacquiao had opened over Diaz’s eye as he told him, “Get your head under his chest. You won’t get hit half as much.’’

Sound advice but easier said than done because to get that close to Pacquiao, Diaz had to walk through a swarming bee attack of leather. Frankly, while not getting hit half as much as he was might be preferred it would also have been half again too much to survive.

Surely Diaz understood this. He has been a professional for more than a decade, having turned pro in 1996 after having fought at the Olympic Games in Atlanta. In fact, in his corner was one of his teammates, a former champion already beaten into retirement named Fernando Vargas. Vargas was there to encourage his friend but having been on the wrong end of a few beatings himself Vargas understood he was seeing a man pressing on despite being completely outclassed.

The latter was not because of any failing on Diaz’s part. He did all his skills would allow and he did it for longer than anyone had a right to expect he would. Most importantly, he did it long after he knew all the instructions in the world were not going to prevent this beating from continuing.

Yet Diaz kept coming forward, kept looking for an opening to land the kind of wonder punch that first made him a champion two years ago when despite trailing badly on all three judges cards in the 10th round he knocked out Jose Armando Santa Cruz with a blind shot, followed by a furious flurry of punches that left Santa Cruz unable to protect himself and made Diaz an unexpected champion.

Diaz would be the first to acknowledge that his skills are limited. He defeated Santa Cruz despite a face full of bruises and he beat the fading Mexican legend Erik Morales despite having one eye half closed in his first title defense.

He did more simply by winning the lightweight title and defending it twice than many people thought him capable of, but what he did against perhaps the best fighter in the world, Pacquiao, was something he can always be proud of.

He was a warrior to the end. A warrior on a night when it was obvious early that he was outgunned and not going to win. A warrior who came back to his corner after the sixth round with blood smeared across his right cheek and flowing into his eye and out of his nose and said to Strickland, “I can handle his punches, (but) he’s just too fast.’’

What he was saying was that he could take what Manny Pacquiao was dishing out. He could accept the pain and the power and continue to come forward. What he could do nothing about was the speed with which those punches rained in on him.

So for two more rounds Diaz tried to leap in and land the kind of punches that had saved him against Santa Cruz. He threw when he could but more and more he had to cover up as Pacquiao, now supremely confident, kept inundating him with flurries that more and more often were stopped by Diaz’s face rather than his arms and gloves.

Early in the fight Diaz had his hands high to protect his face. Still some of Pacquiao’s punches got through because there were too many of them and they came at him too fast to block them all. As the fight wore on and his blood began to leak out of him, fatigue set in and by the end of eight round HBO boxing analyst and Hall of Fame trainer Emanuel Steward was saying the fight should be stopped to protect Diaz from his own bravery. As Steward spoke Diaz sat on a stool in his corner, his aides desperately trying to stop a cut that never ceased bleeding as the referee came in to take a hard look at him.

“I can still see!’’ Diaz snapped back at referee Vic Drakulich and Drakulich walked away one more time, doubt about the wisdom of his decision very likely swirling in his head.

Then came the bell for the ninth round. Diaz pushed himself up and looked across the ring at a fighter he now understood was his superior. His left eye was swelling with an angry purple bruise beneath it. His right eye was again filling with blood from the cut above it and the bridge of his nose was cracked open.

Long ago enough evidence had piled up on his face to end his trial but no one did and so he came out to try again to find some magic. Instead he found himself face first on the floor midway through the round, finally broken by a short left hand he never saw that crashed into his jaw, snapped his head around in two directions like a bobblehead doll in the back window of a moving vehicle and then he crashed to the floor face first.

As he landed Steward said, “It should never have got to that.’’ He was right…unless you asked David Diaz, a man who had come to fight that night against long odds and fight he did.

He fought until there was no more fight left in him and then he fell. At his expense, Manny Pacquiao had furthered his legend. But Diaz had written his own legend in red. He was no longer a champion but he was still a fighter. A fighter to the end.

“We wanted him to go to the hospital,’’ said Top Rank promotions publicist Lee Samuels. “He was really beaten up in the locker room but he insisted on going to the press conference. He said that’s what he needed to do to acknowledge the new champion.

“So that’s what he did. Then we put him in a stretcher and took him to the hospital.’’

As things turned out, Diaz suffered only flesh wounds, it appeared. He was sad to lose, to be sure, because he had not trained for two months and then come to Las Vegas to leave town the way most people do – beaten up.

But he left knowing this: he’d lost a fight but he never lost heart. He lost a fight but not the will to fight. He was beaten up by a better boxer but he was never beaten down.

So the fact is David Diaz left Las Vegas the way he came in. He left a champion.