NEW YORK -- Up and down and up the stadium hallways were Serena-minded people whose innards had just gotten a good rattling from a two-hour palpitation of a sporting event.

"My heart was pounding," said Oracene Price, Serena Williams' mother and co-coach.

"I'd be lying if I said I wasn't starting doubting at 3-5" in the third set, said Sasha Bijan, Williams' longtime hitting partner.

"It was tough because, I mean, she was not understanding what was happening to her," said Patrick Mouratoglou, the Parisian tennis-academy honcho whom Williams began consulting this summer after a galling first-round loss at the French Open.

And as an anticipated U.S. Open rout morphed into a rousing U.S. Open final, witnesses spotted issues. Price: "When you get older, you feel like you have more to lose." Bijan: "She just wasn't playing her best game, and …" And Mouratoglou, diagnosing end-of-Olympic-summer exhaustion: "She lost her game. She just stopped moving, so she was in a bad position to hit the ball. She was losing her balance. … She was lost on the court."

So, what rescued Serena Williams in a drama that went from flattering Williams to flattering Victoria Azarenka to flattering the entire women's game to flattering Williams yet again? What do you call that knack? "Resiliency" doesn't quite cut it. "Will" can't quite describe it. In fact, there might not be a word for it, for that inner gizmo that pushed her from 6-2, 2-6, 3-5 and two points from destruction to 6-2, 2-6, 7-5 and many tiers of elation.

It might defy terminology because of its rarity, which stems from its immediacy. Williams simply can pluck her game from wreckage with startling haste. It is almost mystifying. It certainly defies the laws of momentum, which tend to require some sort of hints or advance notice before a shift.

"Being able to play that level of tennis after losing her level that much, it's something I've never seen in tennis," Mouratoglou said. "Never. She couldn't hit two balls in a row on the court, and suddenly when she's 5-4 she's back to what she was in the first set. … Suddenly she got balanced. Only Serena could have done that."

So here came a backhand screaming up the line to close an 11-shot rally and clinch the hold for 4-5. Here came a crushed forehand cross-court return on the first point as Azarenka served for the match. And here came a zooming forehand up the line, a shrieking forehand up the line, two cross-court backhands that insisted upon deuce when Azarenka held a game point toward 6-6. Williams made 45 unforced errors and 19 in the third set, yet in the final four games reduced that imprecision to a paltry two.

Such a bewildering capacity helps explain how Price felt certain of victory after Williams held serve in the ninth game of the third set. ("I have watched a lot of tennis," she said, smiling.) It's there in how Williams herself said, "I never, never quit." And it's there somewhere as Bijan completed his thought: "She wasn't playing her best game, and to be able to come back from 3-5, you've got to give Serena credit." And while surely Azarenka could have benefitted from more Grand Slam final experience (two berths, to 19 for Williams), she also did not commit rationalization when she said, "I have to say, you know, Serena produced some amazing tennis. I feel like I could have done a little bit better, but there was nothing that I did absolutely wrong."

In the six three-set finals among her 15 Grand Slam titles, Williams has gone 6-0 against Venus Williams (twice), Lindsay Davenport, Justine Henin, Agnieszka Radwanska and No. 1-ranked Azarenka. In four of those six, she has won the first set but lost the second, indicating mastery at ship-righting. You might have forgotten that forte, though, in the jarring way this final fled her grip after the first set.

Williams had won Wimbledon and annihilated both the Olympics and her U.S. Open draw coming into Sunday afternoon. She had won all 12 of her U.S. Open sets and lost only 19 games. She had us bookishly looking up autocratic Grand Slam runs, such as Martina Navratilova in the 1983 U.S. Open (19 games lost) or Steffi Graf in the 1988 French Open (20 games lost) or Chris Evert in the 1976 U.S. Open (12 games lost in only six matches). Some errant wise guys -- hi -- suggested that the continuation of the women's singles event constituted a waste of precious electricity.

Then Williams tore through the first set with 16 winners to two for Azarenka.

Then Williams lost her balance and her game.

"Well, she's a human being, you know, who has two feet, two legs, you know, two hands," said Azarenka, a big admirer of Williams. "It's understandable."

The thing careened into the shocking until the New York crowd got a fresh appreciation for Azarenka, the Australian Open champion. Williams' first serve, the most decisive weapon in tennis, unforeseeably wandered away (49 percent after the first set). Williams even got called for a second-set foot-fault, a throwback to a 2009 semifinal when she infamously lost her mind at a lineswoman, except that this time she kept her cool and limited her protest to a glower at the linesman, who chortled. It became the first three-set U.S. Open women's final since Graf-Monica Seles in 1995. It meandered and enthralled.

In post-match remarks loaded with respect, Williams said, "I really was preparing my runner-up speech, 'cause I thought, Man, she's playing so great."

Amid stakes so high and twists so compelling, one player or the other figured to wind up devastated, face in a white towel, uttering quotations such as, "It really, really hurts." The other figured to say things such as, "This is more exciting to win because you don't know what's coming, you don't know what to expect, and then you get it. This is the best feeling, I think, in tennis."

That the former turned out to be Azarenka, and the latter Williams on sustaining a summer she called "amazing," owes to Williams' power and experience and resolve, but also to a capacity for instant resurrection almost certainly never seen before in tennis. Never.