Serena Williams of the US is congratulated by Caroline Wozniacki of Denmark during their WTA Finals singles semi-final tennis match at the Singapore Indoor Stadium October 25, 2014.[Photo/Agencies]

SINGAPORE - Serena Williams is in the final of the WTA Finals after beating Caroline Wozniacki in a third-set tiebreaker on Saturday, winning 2-6, 6-3, 7-6 (6) to remain on course for a third-straight title in the season-ending championships.

Wozniacki served for the match at 5-4 in the third set but Williams broke back and prevailed in the tiebreaker on her third match point after trailing 4-2.

Williams' opponent in Sunday's final will be the winner of the late match Saturday between Simona Halep and Agnieszka Radwanska.

The American has now won 10 of 11 matches against Wozniacki, including this year's US Open final and two other 2014 matches in which she recovered from a set down.