The No.6-seeded Chan sisters, Hao-Ching and Yung-Jan, were actually the last team to beat Hingis and Mirza, in the semifinals of Cincinnati right before the US Open, and for the first hour of the match it looked like they might be on to something again, as they rallied from 5-2 down in a tie-break - and fought off two set points, first at 6-5 then again at 8-7 - to squeak out the 67-minute first set.
But the No.1-seeded Hingis and Mirza went right to work from there, winning 14 points in a row to take the second set in just 25 minutes and clinching victory after a match tie-break, 6-7(9), 6-1, 10-8.
"I think the first set, we were probably a bit unlucky not to win," Mirza said after the match. "We got a pretty terrible call at that break point to go up 3-2, then after that we probably should have won that tie-break because we were up the whole time. All credit to them, though, they came up and made us hit one extra ball. They probably played us the best out of the last five or six times we've played them.
"It was a tough tie-break to lose. We could have easily mentally lost it. But we just tried to get ourselves together again. We wanted to keep it together, and really use our experience to get it back."
"We stayed aggressive and tried to keep pushing and creating more opportunities, and all of a sudden things started happening," Hingis said. "It took so much energy to be down all the time and have to come back, because we had so many break chances, chances to win the set, but we just tried to keep our level and stay on top of them. Once we were in the super tie-break, we were always winning."
And so, they now have eight WTA doubles titles on the year at Indian Wells, Miami, Charleston,Wimbledon, the US Open, Guangzhou, Wuhan and Beijing. The last four - the US Open, Guangzhou, Wuhan and Beijing - have come in what is now a four-tournament, 18-match winning streak.
They're the first team to win eight WTA doubles titles together in a year since Sara Errani and Roberta Vinci won eight in 2012. The last team to win more was Cara Black and Liezel Huber's 10 in 2008.
The Swiss-Indian duo's next tournament together will be the BNP Paribas WTA Finals Singapore presented by SC Global, but one of them - the Swiss - is playing one more tournament in Tianjin.
"Sania is going home," Hingis said.
"I have stuff at home to do. She's actually playing with a Chinese next week," Mirza said.
"I'm looking forward to Tianjin," Hingis, who played with Flavia Pennetta at the International-level event last year, added. "I was there last year, and it's a great tournament, and a beautiful stadium."