Cincinnati, Aug 20 (IANS): The Indo-Swiss tennis combine of Sania Mirza and Martina Hingis started their $2,701,240 Cincinnati Masters campaign with a with a straight sets win to enter the women's doubles quarterfinals here.

In the second round on Wednesday, the top seeds took just an hour and 22 minutes to beat unseeded German-Polish pair of Julia Goerges and Klaudia Jans-Ignacik 7-6(3), 6-4 on the outdoor hard courts of the Lindner Family Tennis Center.

In one of the most topsy-turvy matches of the tournament yet, both pairs broke the other no less than four times each in the first set, eventually leading to the tie-break. Sania and Martina, who had received a first round bye, proved better when it mattered to win the tie-break 7-3.

The reigning Wimbledon champions struggled with their service games, committing as many as four double faults to give away points at crucial times of the set.

Julia and Klaudia broke the top seeds once more in the second set but the Indo-Swiss combine came out better to break the unseeded combine twice, which was enough to seal the set and the match.

Overall, Sania and Martina won 73 of the 132 points played in the contest.

Indo-Romanian fifth seeds Rohan Bopanna and Florin Mergea will play their men's doubles second round against French combine Pierre-Hugues Herbert and Nicolas Mahut on Thursday.