The top seeded Indo-Swiss pair, which surrendered the top spot after defeats in Stuttgart and Madrid, saved a set point in the second set tie-break.
They won titles in Indian Wells, Miami and Charleston in an extraordinary good run after joining forces. They are now 18-2 together since March, a 90% winning percentage.
Awaiting them in the final will be No.3 seeds Timea Babos and Kristina Mladenovic, who beat No.8 seeds Alla Kudryavtseva and Anastasia Pavlyuchenkova in the first semifinal of the day, 6-2 6-4.
Sania and Martina beat Babos and Mladenovic in their only previous meeting in Miami 6-2 6-4.

Latest News from Sports News Desk