Sania Mirza and Bethanie Mattek of US went down in straight sets to Italy's Maria Elena Camerin and Gisela Dulko of Argentina in the doubles semifinal of the Bank of West Classic tournament at Stanford, USA.

The fourth-seed pair of Dulko and Camerin carved out a 6-4, 6-3 win to make a place in the final of the $ 600,000 Tier II event.

Sania had reached the finals last week at Mason in the Tier III WTA event, partnering with Poland's Marta Domashowska, which also fetched her the career best doubles ranking of 31.