The unseeded Indian pair took one hour and 15 minutes to carve out a 3-6, 6-4, 10-5 win.
Meanwhile in the juniors category, top seeded Yuki Bhambri continued his winning run to the quarter-finals. He defeated 13th seed Croat Dino Marcan 6-3, 6-1 in the third round of the junior boys' singles competition. 2008 runners-up, Sania-Mahesh dropped their serve twice in the first set and wasted one break point to hand the opener to their opponents.
In the next set, they missed chances aplenty but were successful in converting three breakpoints out of the seven to make it one set all. In the super-tie breaker, the Indians held their nerves to emerge winners.
Sania and Mahesh will face the Czech pair of Iveta Benesova and Lukas Dlouhy next.
OneIndia News (With inputs from Agencies)