Sania and Cara had won Pan Pacific Open in Toyko last week and the two players have now won nine matches on the trot.
It is fifth title of the season for the Indian ace and 19th overall.
Sania had won the New Haven event with Chinese Zheng before teaming up with Cara.
Early in the season, she captured titles in Dubai and Brisbane with American partner Bethanie-Mattek Sands.
After Bethanie-Mattek decided to put all her energy on the singles, Sania has teamed up with four different partners -- America's Liezel Huber, Italy's Flavia Pennetta, China's Jie Zheng and now Cara.