Former champion Tamarine Tanasugarn suffered a second-round exit in the Hyderabad Open.
The sixth-seeded Thai player, who won the title in 2003, was upset 6-2 6-1 by Sun Tiantian of China.
But there were no such problems for top seed Li Na of China and second seed Anna Lena Groenefeld.
Li beat Argentina's Maria Emilia Salerni 6-2 7-5 and Groenefeld cruised past Slovakia's Jarmila Gajdosova 6-3 6-2 to reach the quarter-finals.
In other second-round matches, Ukraine's Alyona Bondarenko beat Melinda Czink of Hungary 6-3 6-7 (7-2) 6-4 and Israel's Tzipora Obziler beat Evie Dominikovic of Australia 6-3 6-2.