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In the previous two rounds, Liang and Wang had accounted for seeds Caroline Garcia and Katarina Srebotnik and Timea Babos and Kristina Mladenovic, but were no match for the WTA's preeminent pairing, lasting just 66 minutes.
The top seeds made a flying start, Mirza swatting away a volley to break in the second game.
This set the tone for the rest of the contest as Hingis and Mirza romped towards their ninth final of the season.
The 6-2, 6-3 success extends their unbeaten streak to 16 matches, a sequence stretching back to the Cincinnati semifinals.
And meeting them in the final will be their conquerors on that August day, Chan Hao-Ching and Chan Yung-Jan, after they won an altogether more dramatic encounter against Casey Dellacqua and Yaroslava Shvedova.
During a tense finale the siblings held their nerve to triumph, 6-3, 6-7(7), 12-10, and in the process become the seventh team to book their spot at the BNP Paribas WTA Finals Singapore presented by SC Global.