Ageless Venus Williams continued her remarkable renaissance with a three-set semi-final victory over Caroline Garcia to set up a mouthwatering WTA Finals decider with in-form Caroline Wozniacki. Williams, 37, came from a set down to triumph 6-7, 6-2, 6-3 in two hours and 29 minutes at the Singapore Indoor Stadium. The American will be aiming to end a nine-year WTA Finals title drought when she plays Wozniacki on Sunday. Garcia, playing in her WTA Finals debut, looked gassed at times as the match wore on, having played a two-hour-and-19-minute marathon against Wozniacki on Friday. Williams claimed the decisive break in the eighth game of the third set before her clutch serving saw her overcame three break points and claim a memorable victory. "Every time I thought I was close, she [Garcia] would play amazing," Williams said after the match. "It is hard to produce your best tennis at the end of the year because you've given so much. Nothing is easy. It's amazing to almost be in the winner’s circle." Both players were coming off impressive victories to qualify and continued their rich form during a high-octane opening set. They traded breaks early before Garcia squandered a set point in the 10th game. Consecutive double faults from Williams early in the tiebreak handed the world No 8 the initiative and she capitalised to win the first set lasting 65 minutes. Williams looked in grave trouble when she faced two break points in the first game of the second set but she fought back to hold serve and then broke Garcia in the next game. Williams's trademark serve and her powerful groundstrokes started dictating, as she stormed through the second set in just minutes. <strong>__________________________________</strong> <strong>Read more:</strong> <strong>__________________________________</strong> Earlier on Saturday, Wozniacki stood her ground in the face of some early pressure before pulling away from Karolina Pliskova to grind out a 7-6, 6-3 victory in a captivating semi-final showdown at the WTA Finals. The victory, completed in just under two hours, was built on Wozniacki's resilience, consistency and greater variation on the key points, and put the 27-year-old Dane into her second final in the eight-woman event after losing in 2010. Wozniacki goes on to meet the winner of the second semi-final between Venus Williams and Caroline Garcia later on Saturday, while Pliskova is left to rue a defeat that prevents her from being able to replace Simona Halep as world No 1. "We have had a lot of close matches this year and I was hoping today was my turn. It feels great to be in the final and I have been playing some great tennis this week," Wozniacki said in a courtside interview. Both players raced out of the blocks in their previous three matches in Singapore but perhaps mindful of what was at stake, they made a cagey start to their semi-final, unable to stamp any sort of authority on proceedings. Pliskova was the aggressor and found more success when she committed to her attacking shots, while Wozniacki was content to use her supreme court coverage and stonewall defence to stay in touch. The first five games went with serve until the Czech edged ahead by instigating a run of four straight breaks of serve as Wozniacki staved off three set points in the 10th game stay alive in the set and eventually forced a tiebreak. The Dane then raced into a 6-1 lead over the sleepwalking Pliskova before the Czech rose from her slumber to first save all five set points and then fashion three more of her own, which Wozniacki somehow managed to survive. Wozniacki continued to cover every inch of the court to set up another set point, her sixth, with more defensive brilliance, and the former No 1 sealed the opener 11-9 in the breaker when Pliskova found the net with a backhand. The Dane was full of confidence and attempted to break free with an early break in the second set to move 3-1 ahead but Pliskova refused to buckle and stormed back by stepping in to take her shots early to get the contest back on serve. Wozniacki changed tactics again, however, and opted to push the ball into the corners to force Pliskova into some vital errors as she struggled out of position and the Dane broke once more for a 5-3 lead. This time there would be no way back for Pliskova as Wozniacki sent a backhand crosscourt winner past her stranded opponent to storm into the final. "It was a little bit crazy, managing to come back from those set points and then not feeling so good about myself after being 6-1 up in the tiebreak," Wozniacki said. "It was kind of a roller-coaster and I am just happy that I got the first set under my belt."