Sania Mirza and her Polish partner Marta Domachowska moved into the semifinal after a hard fought 6-4, 5-7, 7-6 win over the Chinese-Uzbek pair of Meng Yuan and Varvara Lepchenko at the Cincinnati Open.
The third seeded Indo-Polish pair will now take on the winners of the other quarter-final between the British-Russian pair of Anne Keothavong and Alla Kudryavtseva and Chin-Wei Chan of Chinese Taipei and Tetiana Luzhanska of Ukraine.
Sania and Marta were given a tough fight by their unheralded opponents, who came back strongly after losing the first set, but eventually ran out of steam in the close to three-hour long match.
Meng and Varvara took the third seeds by surprise in the second set and matched them shot for shot as they made a comeback into the match. Sania and Marta tried every trick in the book but the unrelenting Chinese-Uzbek pair kept coming at them -- breaking them twice in the process -- to equalise and take the match into a decider.
The third set proved to be a battle of equals as there was hardly anything to choose between the two pairs, who broke each other thrice, taking the set and the match into a tie-breaker.
Sania and Marta held their nerves and got the better of their unseeded rivals who looked drained after the long battle. The Chinese-Uzbek pair failed to raise their game at the crucial juncture in the tie-break and bowed out of the tournament.
Meanwhile, Sania is also through to the quarter-final of the singles competition. She faces a tough opponent in the form of top seed Patty Schnyder of Switzerland.