Sania Mirza and Chia-Jung Chuang of Chinese Taipei continued their good work as they registered yet another upset win over second-seeded Anabel Medina Garrigues and Virginia Ruano Pascual 6-3, 7-6 (4) to storm into the doubles semi-finals of the Sony Ericsson Open here yesterday.

The unseeded Indo-Taiwan pair put up a clinical performance in the first set, but Garrigues and Pascual showed stiff resistance in the next one before going down in the tie-breaker. In the quarter-final, Sania and Chuang had stunned eighth-seeded Italian Flavia Pennetta and Russian Maria Kirilenko 4-6, 7-6 (5), 10-4 on Monday.

Sania is now the lone Indian in the fray after Leander Paes and his Czech partner Lukas Dlouhy were shocked by Czech-Slovak pair of Frantisek Cermak and Michal Mertinak 3-6, 3-6 in the men's doubles second round yesterday.