Los Angeles: Sania Mirza and Bethanie Mattek overcame a fighting Russian pair of Elena Vesnina and Vera Zvonareva to book a semi-final berth in the $600,000 WTA East West Bank Classic tournament here.

The Indo-American pair, seeded second, pipped the Russian duo 6-3, 1-6, 10-8 in an hour and 14 minutes in the quarter finals of the tier ii hard court event last night.

Sania-Mattek did not once drop their serve in the first set and converted two of the four breakpoints to take the lead.

However, they surprisingly lost the momentum and allowed Vesnina-Zvonareva combination to overpower them in the next.

Sania and partner dropped their serve thrice in the second set and also squandered the only breakpoint.

However, they got their act together in the tiebreaker to prevail over the Russians and move to the last four, where they will face the winner of the match between Eva Hrdinova/Vladimira Uhlirova and Ayumi Morita/Ai Sugiyama.