What a weird Las Vegas hangover, even if it does lack a tiger and a naked man in the trunk.

Manny Pacquiao conked out and boxing woke up.

The man often said to be propping up the sport needed propping up himself, which somehow wound up propping up the sport.

Pacquiao fell, Mitt Romney gasped, Manila mourned, Mexico City raved and the near future brimmed. People actually chattered about the fight that happened rather than the fight that still hasn't happened. And 2013 sits ahead looking pretty sumptuous, with possibilities of Pacquiao-Marquez V, or Marquez-Mayweather II, or Pacquiao-Bradley II, plus a Mayweather-Pacquiao topic probably most find dormant but some find renewed.

Boxing. Who knew.

The five rounds and two minutes and 59 seconds of Pacquiao's fourth bout with Juan Manuel Marquez seem to have reiterated that the sport is fascinating, that there's a reason it's the subject of two Best Picture winners plus another that didn't win Best Picture but won merely the critical-consensus best film of the 1980s. Pacquiao-Marquez IV showed again the exponential value of one punch.

One punch can relight the past, overwhelm the present and flatter the future. That's a lot of terrain for an entity that might have traveled less than a foot.

The past glows again for Pacquiao as one punch reminds us that one punch can happen, lending an even greater impression of the agility and skill and concentration required to avert it for so long. Before the third round on Saturday night, Pacquiao had not gone down in almost a decade. Before the final second of the sixth, he had not gone down for good since 1999 in southern Thailand. "He knows he walked into a punch," his trainer Freddie Roach said. "He made a mistake. He got careless. That happens in boxing."

Yes, well, apparently we need some reminding, because so impressively long it did not happen to Pacquiao.

"Losing a fight, getting knocked out, is not death!" promoter Bob Arum said. "Do you understand?" And to exhibit it, Arum dug back into the athletic prehistory of the 1960s: "Sandy Koufax -- I'm showing my age -- can get shelled by the Giants and come back the next time and throw a no-hitter."

Arum has fights to promote, and Koufax would get his chance four days rather than six months later, but the picture remains: If losing is so humdrum, reasonably, it's an elevated level of amazing that Pacquiao did not do it for seven years, even if he may have done it realistically in Pacquiao-Marquez III, and even if he may not have done it when he finally did it last June against Timothy Bradley.

The present has gone blurred because a punch can do that. Lost is the reality that Pacquiao led the fight, that he looked dazzling for much of the fight and that he might even have lived up to Roach's pre-fight assessment of "the best Manny Pacquiao I've seen in a long time." Was he, for the 17 minutes and 55 seconds leading up to his blundering aggression at a round's end?

As Arum said, "I don't think there was one person whether on television or here that saw that fight that wasn't just blown away." Does walking into one diminish how the rest of it looked? Should a guy retire because of one punch if the rest of the bout soared with fur-flying aggression?

Really?

With one whoosh and one punch and one collective gasp comes one global wave of reassessment, even as Pacquiao landed in the Philippines on Wednesday and vowed more fights after some months off. Does one punch validate that it mattered that Marquez supposedly trained for four-and-one-half months while Pacquiao supposedly trained for two? Does one punch validate that Pacquiao has too many side interests, from his work as a congressman to his rededication to religion?

Yet what one punch did to the past and present still bows to what it does to the future.

It takes Pacquiao's veneer of invincibility that had shown cracks in recent years and it goes ahead and shatters it, giving us the spectacle of him in vulnerable repair. If anything, that is more fascinating than dynasty. As it promises to fan out over all ensuing bouts, the punch blesses us with the alluring question of what one punch might do to a fighter's psyche from here on, especially as his wife and mother plead to the Filipino media for a retirement. You might see the teenagers in the Manila streets selling food and cigarettes, and you might surmise it took some sort of Superman to clamber up out of all of that, but how might that same fathomless strength lend itself to rebounding from trauma?

And outside even of that, it takes a sport properly said to teeter toward another fade with its stars aging, and it slaps a must-see level on any big bouts of 2013, even if none of them turn out to be Mayweather versus Pacquiao. It makes boxing part of the anticipatory sporting mindset of New Year's Day, a post it has occupied only in certain devoted pockets this young century.

Boxing-who-knew, because what happened last Saturday night -- and what will turn up in replay this Saturday on HBO -- became one of those sports moments so jarring that the brain has to catch up to it, the red eyes have the feeling of some mass hallucination and the head hurts but with new suspense, an odd twist for a hangover.