CINCINNATI -- Serena Williams wilted in the Ohio heat Sunday night at the final of the Western & Southern Open.

She dominated the first set, then fell apart, giving No. 2 Victoria Azarenka a chance to rally for a 2-6, 6-2, 7-6 (6) win that ended Williams' 14-match winning streak. It was reminiscent of their finals match at the U.S. Open last year, when Williams took the last four games to win 6-2, 2-6, 7-5.

Williams had never won a Cincinnati title. She was trying for her second championship in two weeks, fresh off her championship in Toronto.

Williams has dominated on the tour, going 60-4 this season. She has never done well in Cincinnati, and was eager to win on Sunday for a career-best ninth title of the season. All the statistics were in her favor -- a 12-2 career record against Azarenka, including that U.S. Open title last year.

She won the first set in 26 minutes, dropping only 11 points. Then, she got sloppy in a second set that bogged down. The sixth game went to deuce 12 times before Williams held serve on the 30th point. Williams appeared to wear down and lost the set 6-2.

Williams broke Azarenka and took the decisive set to a tiebreaker. She led 5-4, then lost the next two points off her serve, allowing Azarenka to finish it off in 2 hours, 29 minutes.

With her semifinal win over Li Na on Saturday, Williams clinched the 2013 Emirates Airline U.S. Open Series women's title and can earn a $1 million bonus if she wins the U.S. Open.