Serena Williams repeated as US Open women's champion by holding off a battling Victoria Azarenka of Belarus 7-5 6-7(6) 6-1 in a windblown final at Arthur Ashe Stadium on Sunday.

Williams bounded in a series of jumping jack leaps after Azarenka's backhand sailed long on the second match point of the thrilling, two-hour 45-minute final.

In winning the title rematch against second-seeded Azarenka, world number one Williams claimed her fifth US Open crown and 17th career grand slam singles title.

The big-hitting American, who turns 32 later this month, became the oldest US Open women's winner since tennis turned professional 45 years ago, eclipsing Australian Margaret Court, who was 31 years and 55 days when she won the title in 1973.

It had looked like it was going to be plain sailing for Williams after she won the first set, boosted by a late break in the 11th game for a 6-5 lead and then served out a love game.

Williams, who earlier looked confounded by the gusty wind that affected service tosses and the direction of bounces off groundstrokes, finally settled into a rhythm and surged to a 4-1 lead in the second set after Azarenka double-faulted three times in the fifth game.

But the Belarusian broke right back for 4-2 and rode that momentum.

Twice Williams served for the match, at 5-4 and again at 6-5, but Azarenka rose up to break the American's serve and force a tiebreaker.

Williams raced to a 3-1 lead in the decider, but Azarenka won five of the next six points to seize a 6-4 lead and send the championship match to a third set when Williams belted a backhand long to lose it 8-6.

The third set stayed on serve until the fourth game when another double fault, her seventh of the match, sank Azarenka and handed Williams a 3-1 lead.

Williams broke Azarenka two games later for good measure to make it 5-1 and then claimed victory when the Belarusian sent a backhand long on the second match point.

"Victoria, you played unbelievable," said Williams at the trophy ceremony.

"What a great match and what a great person. Vika is such a great opponent, she's such a great fighter. It was never over until match point," added Williams, who collected the $2.6 million top prize and pocketed an addition $1 million bonus for having won the US Open run-up series of tournaments.

Azarenka said she had been beaten by the better player.

"It is a tough loss. But the best player deserves the win today. I gave it all again this year," said Azarenka, who lost 7-5 in the third set to Williams in last year's final.

"We gave it everything we got."

List of US Open women's singles winners:

2013 Serena Williams (US) beat Victoria Azarenka (Belarus) 7-5 6-7(6) 6-1 2012 Serena Williams (US) beat Victoria Azarenka (Belarus) 6-2 2-6 7-5 2011 Sam Stosur (Australia) beat Serena Williams 6-2 6-2 2010 Kim Clijsters (Belgium) beat Vera Zvonareva (Russia) 6-2 6-1 2009 Clijsters beat Caroline Wozniacki (Denmark) 7-5 6-3 2008 Serena Williams beat Jelena Jankovic (Serbia) 6-4 7-5 2007 Justine Henin (Belgium) beat Svetlana Kuznetsova (Russia) 6-1 6-3 2006 Maria Sharapova (Russia) beat Henin 6-4 6-4 2005 Clijsters beat Mary Pierce (France) 6-3 6-1 2004 Kuznetsova beat Elena Dementieva (Russia) 6-3 7-5 2003 Henin beat Clijsters 7-5 6-1 2002 Serena Williams (US) beat Venus Williams (US) 6-4 6-3 2001 Venus Williams beat Serena Williams 6-2 6-4 2000 Venus Williams beat Lindsay Davenport (US) 6-4 7-5