Sania Mirza and her American partner Bethanie Mattek stunned formidable Taipei duo of Yung-Jan Chan and Chia-Jung Chuang to book a doubles semi-final berth at the USD 2,100,000 Pacific Life Open WTA Championships.

The Indo-US combination prevailed 7-5, 4-6, 11-9 in a gruelling quarterfinal encounter of the tier I event.

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.

Bhupathi-Knowles out

Meanwhile, Indian challenge ended in USD 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.