They stunned eighth seeds Maria Kirilenko and Flavia Pennetta in a gruelling three-setter for a place
Sania and Chuang shocked the fancied Russian-Italian pair 4-6 7-6 (5) 10-4 to enter the last-eight stage.
The unseeded Indo-Taiwanese duo will next take on the winners of the match between the Argentine-Israeli team of Gisela Dulko and Shahar Peer and the Spanish combine of Anabel Medina Garrigues and Ruano Pascual.
The other Indian in fray at the event is Leander Paes, who, partnering Czech Lukas Dlouhy, has reached the pre-quarters of men's doubles.
Mahesh Bhupathi, who teamed up with Bahamian Mark Knowles, crashed out after losing in the first round itself.