INDIAN WELLS, Mar 20: Sania Mirza and her American partner Bethanie Mattek stunned formidable Taipei duo of Yung-Jan Chan and Chia-Jung Chuang to book a doubles semifinal berth at the $2,100,000 Pacific Life Open WTA championships here.

The Indo-US combine prevailed 7-5, 4-6, 11-9 in a gruelling quarterfinal encounter of the Tier I event, last night.

Chuang and Chan are world number nine and 10 while Sania and Mattek stand at 25 and 36 in the WTA charts, respectively.

The winners next take on Chinese third-seed pair of Zi Yan and Jie Zheng, who defeated Czech-Polish combine of Iveta Benesova and Agnieszka Radwanska 6-0, 6-4 in their last eight encounter.

Meanwhile, Indian challenge ended in $3,589,000 men's Master Series event with the straight set defeat of Mahesh Bhupathi and his partner Mark Knowles.

The sixth seed Indo-Bahamas duo lost their quarterfinal match 3-6, 4-6 to fourth seeds Jonathan Erlich and Andy Ram of Israel.

Leander Paes and his Australian partner Paul Hanley had also crashed out in the quarterfinals.