NEW YORK: Serena Williams, through sheer force of will as much as her skill with the racket, beat world number one Victoria Azarenka 6-2 2-6 7-5 in a dramatic US Open final on Sunday to capture her 15th singles grand slam title.

On her best behaviour but struggling to subdue an opponent seven years her junior, Williams provided an everlasting reminder of her incredible fighting qualities as she became the tournament's oldest women's champion in nearly four decades.

Already one of the greatest players to grace the game, the American's longevity adds new credence to her place in the sport's pantheon with Sunday's victory coming almost 13 years to the day she won her first US Open as a teenager in 1999.

“I don't consider myself the greatest,” she said.

“I just consider myself a tennis player who's trying to do the best I can.”

Her clash, against the top player in the world this year, lived up to all expectations and more as the pair traded blows for almost two and a half hours at Flushing Meadows.

Azarenka, who won her maiden grand slam title at the Australian Open in January, led 5-3 in the deciding final set and was within two points of victory when Williams lifted and reeled off the last four games to capture her fourth US Open crown.

“I have no regrets. I felt like I gave it all there,” said Azarenka.

“Could it have gone my way? Probably, yes. But it didn't and it really, really hurts.”

SIGNS OF NERVES

The opening exchanges gave few clues of what was to come as Williams romped through the opening set in 35 minutes with two service breaks and 16 stunning winners.

But the Belarusian returned to the court with renewed determination and found a way to penetrate her opponent's serve.

As Williams started to show the first signs of nerves, Azarenka seized her opportunity, breaking her serve twice, and for the first time since 1995, the women's final at Flushing Meadows was forced into a winner-takes-all third set.

The capacity crowd at the bear-pit that is the Arthur Ashe Stadium centre court roared with excitement as the two combatants ran themselves to the point of exhaustion, producing some breathtaking shots as the stakes rose.

Williams kept her cool, even when she was called for a foot fault, avoiding a repeat of her petulant behaviour at Flushing Meadows in the 2009 semi-final against Kim Clijsters and last year's final with Sam Stosur.

After facing serious health issues, including the discovery of a life-threatening blood-clot on her lung, in the past 18 months Williams has developed a new perspective about her actions on court.

“I really think a champion is defined not by their wins but by how they can recover when they fall,” she said.

“I have fallen several times. Each time I just get up and I dust myself off and I pray and I'm able to do better or I'm able to get back to the level that I want to be on.”

THE 'GREATEST'

In the third set, it was the American who blinked first and her golden summer, which included winning a fifth Wimbledon title and two gold medals at the London Olympics, looked like coming to an end.

She was two points away from losing but regained her composure when it mattered most by winning the last four games then collapsing on the court at the realisation she had won again, with little more than two weeks before her 31st birthday.

“For me, she's the greatest player of all time. She took the game to the next level,” Azarenka said.

“I congratulated her with all my heart because I felt like she absolutely deserved the win. She was the best player out there today.”

Only Australia's Margaret Court, who had already turned 31 when she won her last US Open crown in 1973, won the title at an older age than Williams but the American is not finished yet.

“My motivation is so up there,” she said. “I just feel like I'm ready for the next tournament.

“I really want to be focused and do well there and just keep the dream alive.”

DJOKOVIC TO PLAY MURRAY

Novak Djokovic completed a weather-halted 2-6 6-1 6-4 6-2 victory over Spaniard David Ferrer on Sunday to return to the men's final.

The Australian Open champion, who had looked lost at windblown Arthur Ashe Stadium on Saturday before the semi-final was suspended due to an approaching storm with 10th seed Ferrer leading 5-2.

“I was a different player,” the second-seeded Djokovic said.

“I felt much more comfortable on the court today than I did yesterday.

“Ferrer was coping with the conditions much better than I did. Yesterday, I didn't have any rhythm, so I didn't mind getting off the court yesterday to be honest and coming in today.”

Blasting winners from both sides and breezing through his service games, Djokovic needed less than two hours to sweep the last three sets and set up a finals showdown against third-seeded Olympic champion Andy Murray of Britain.

Murray, who beat Czech Tomas Berdych in his semi-final, will be aiming for his first grand slam title in the final, which was rescheduled for Monday because of the delays. “It's definitely a huge relief to get through this match.

He's a great competitor,” Djokovic said about Ferrer.

Five-time grand slam winner Djokovic, befuddled by the blustery winds that swept through Flushing Meadows on Saturday, lost his first set of the tournament when Ferrer, 30, held serve when they resumed play on Sunday at the National Tennis Center.

DOMINANT PLAY

That was Ferrer's high point of the day as the 25-year-old Djokovic dominated the rest of the way to reach his ninth grand slam final.

“I don't know, every day is different,” said Ferrer. “Today, Djokovic plays better than me.”

Djokovic blasted 28 winners, double the total of Ferrer, over the last three sets and made just 20 errors against 31 for the Spaniard. He was lethal when opportunity presented itself, converting six of eight break point chances.

“We were all praying for less wind today,” said Djokovic, who has won the last three grand slams played on hard court, including back-to-back Australian titles. “I think he handled the wind much better than I did.

“I came in today as a different player and I'm very happy to get to another grand slam final.”

Djokovic has made seven of the last ninth grand slam finals.

The world number two improved his career record to 9-5 against the hard-fighting Spaniard, who has won five tournament titles this season but was overpowered by the Serb on Sunday.

“Every match is different. Every day is different,” said Ferrer, who won a fifth-set tiebreaker against Serbian Janko Tipsarevic to reach the semi-finals.

Ferrer, who will be returning to Spain for this weekend's Davis Cup semi-final against the United States, was not able to reach his first grand slam final after a fourth appearance in a semi-final, but said overall he was pleased with his showing.

“Of course, I am very positive,” he said. “I reached the semi-final in a grand slam, my second time in a semi-final here at the US Open. I am very happy with me and with my performance.”