Serena Williams survived another tight tussle with Victoria Azarenka to retain her US Open title and win a 17th grand slam singles trophy.
The world number one recovered from losing a second set in which she led 4-1 and twice served for the match to triumph 7-5 6-7 (6/8) 6-1.
Williams' fifth US Open singles success moved her to within one of Chris Evert and Martina Navratilova's 18 slam crowns, but still seven behind Margaret Court's career tally.
It was a rematch of last year's final, when Azarenka also fought back from a set down before serving for the match only for Williams to edge it.
Williams won her first US Open title 14 years ago but never has she been as dominant as this season, with this trophy - her ninth of the year - and second grand slam after a much-cherished French Open triumph.
The 31-year-old also picked up a cheque for $3.6million.
Williams went into the match as a big favourite to hold onto her title having scythed through the draw at Flushing Meadows.
The 31-year-old had dropped just 16 games in six matches, while Azarenka had lost sets against Alize Cornet and Ana Ivanovic and struggled with her serve.
That was a real worry for the Belarusian against the might of the Williams return, and it was no real surprise when she was broken in the opening game.
But there was a strong wind on Arthur Ashe and Williams looked unsettled, shooting panicky looks to her box and appearing preoccupied by her billowing dress and hair as a flurry of errors allowed Azarenka to break straight back.
Azarenka had the confidence of knowing she had won both their hard-court matches this season, including in Cincinnati just before the US Open.
In a long 10th game Williams was called for a foot fault at deuce - bringing back memories of her semi-final against Kim Clijsters in 2009, where raging against a lineswoman cost her a point penalty and the match.
This time she barely flickered, and survived without giving up a set point.
It was a key hold, with Williams breaking in the next game and going on to clinch the set.
Azarenka is the only current player who is able to match Williams' competitive intensity, but the American was on a roll now and appeared on the verge of victory at 4-1 up with two breaks.
However, Azarenka would simply not let go in her pursuit of a first US Open title, and Williams' nerve failed her at the crucial moment.
Twice she served for the match but twice the Belarusian broke back, coming up with some astonishing returns off top-notch Williams serves.
The tie-break was tense and intense, and it was Azarenka who took the initiative as a nervy Williams netted a routine backhand and smashed her racket in annoyance.
That gave the second seed two set points, but Williams saved the first with a big serve before Azarenka netted a forehand.
A third chance arrived, and this time the Belarusian took it, proving equal to a superb Williams serve and drawing the error.
It was an exceptional effort from Azarenka, and a hugely tough set to lose for Williams, but she regrouped quickly.
And she moved ahead 3-1 in the decider thanks to a seventh double fault from her opponent.
The time there was no comeback from Azarenka, Williams breaking again for 5-1 and then clinching victory on her second match point after two hours and 45 minutes when her opponent hit a backhand long.
Williams jumped around the court in celebration as Azarenka sobbed into her towel, a beaten finalist on Arthur Ashe once again.