Doha: Defending champion Venus Williams reached the final of the WTA Championships on Saturday, beating Serbia’s Jelena Jankovic 5-7, 6-3, 6-4.

Venus was plagued by unforced errors as she lost the first set and Jankovic, who was briefly world No. 1 at the start of the year, had chances in the second, particularly when she squandered three break points at 2-2.

Jankovic gained the early advantage in a deciding set in which both players struggled to hold serve but Venus hit back and broke three times to serve for the match at 5-4, clinching victory with a forehand that dropped over off the tape.

“In the first set I couldn’t feel the ball and couldn’t seem to get a ball in,” Venus, who needed treatment on her knee during the match, said in a courtside interview. “But this is my last tournament of the year so I’m giving 1,000 percent.”

On Friday, Jankovic had crushed a leg-weary Caroline Wozniacki to reach the semi-finals while Venus reached the last four without hitting a ball.

On a day when calculators were needed to work out the various permutations in the two groups of four, Wozniacki deservedly also survived for the weekend.

The Dane progressed after Belarussian Victoria Azarenka’s hopes ended in tears when she retired injured in the third set of her match against stand-in Agnieszka Radwanska of Poland.