The fourth seeded Indo-Zimbabwean pair knocked out the sixth seeded American team 6-2 6-1 in the lop-sided quarterfinal contest.
Sania and Cara converted six of the 10 break chances in the match in which they won 52 points to 27 of their rivals.
They next face formidable second seeded pair of Su-Wei Hsieh from Taipei and Shuai Peng from China.
Sania and Cara have not beaten Su-Wei and Shuai in three meetings this season so far.