India's Sania Mirza (left) and Switzerland's Martina Hingis celebrate their 7-6 (12-10), 7-5 win over Taiwanese combination of Hao-Ching Chan and Yung-Jan Chan in the WTA Finals in Singapore yesterday. Pic/Getty Images

Singapore: Indian ace Sania Mirza and Switzerland's Martina Hingis entered the semi-finals of the WTA Finals after beating Taiwanese combination of Hao-Ching Chan and Yung-Jan Chan 7-6 (12-10), 7-5, here yesterday.