Slava Shvedova and Vania King faced Kveta Peschke and Katarina Srebotnik in the first doubles semi.
Kveta Peschke and Katarina Srebotnik will both be fighting for their first titles at the year-end finale.
Petra Kvitova stretched before the first singles semifinal, where she would take on Samantha Stosur.
Sam Stosur built a 75 10 lead with a break point for 75 20 but Petra Kvitova kicked into high gear.
Sam Stosur and Petra Kvitova met at the net after Kvitova recorded a 57 63 63 win over the Australian.
Victoria Azarenka got in the zone ahead of the second semifinal, where she would play Vera Zvonareva.
Vera Zvonareva had won six of nine previous meetings with Vika Azarenka, but this didn't go her way.
Victoria Azarenka was just too strong for Vera Zvonareva, moving into the final with a 62 63 victory.
Flavia Pennetta and Gisela Dulko took on Liezel Huber and Lisa Raymond in the second doubles semi.
Lisa Raymond and Liezel Huber came from 3-6 in the tie-break to beat the defending champs, 46 63 107.
The WTA and the tournament made a huge donation to earthquake relief after the first semifinal match.
Liezel Huber was presented a special crystal trophy for securing the year-end No.1 doubles ranking.
Several stars of the WTA were on hand for a special retirement tribute to Switzerland's Patty Schnyder.
Sam Stosur, USANA's Alan Bergstrom and Stacey Allaster presented a donation to Children's Hunger Fund.
Second alternate Andrea Petkovic struck a pose with one of the tournament posters featuring her image.