Venus Williams won the Wuhan Open on Saturday when her Spanish opponent and fifth-seeded Garbine Muguruza retired with a left ankle injury while trailing 6-3, 3-0.
It was the unseeded Williams' 47th WTA singles title.
"It's not easy when you don't play your best," Williams told Muguruza, adding that "I probably didn't have a chance if you felt well."
Muguruza said she was "very sorry" at having to retire.
Williams rallied from 5-3 down in the third set of the quarterfinals to beat British qualifier Johanna Konta, and she saved a match point during a 5-7, 6-2, 7-6 (4) semifinal win over Roberta Vinci.
Both finalists are projected to make major moves up the rankings — Williams from No. 24 to No. 14 and Muguruza from No. 8 to No. 5, her top-five debut.
Earlier Saturday, Martina Hingis and Sania Mirza beat Irina-Camelia Begu and Monica Niculescu in straight sets in the doubles final.
The winning duo dropped serve three times and had to fight back from a 2-0 deficit in the second set, but the No.1-seeded Hingis and Mirza won, 6-2, 6-3. The Swiss-Indian pairing have seven WTA doubles titles this year and have won their last three tournaments in a row — the U.S. Open, Guangzhou and Wuhan — and 13 straight matches.
Shenzhen Open semifinals postponed
Persistent rain has washed out the semifinals of the Shenzhen Open on Saturday. Both semifinals will now be played on Sunday with the final later the same day.
Top-seeded Tomas Berdych will take on Tommy Robredo on center court while second-seeded Marin Cilic meets fourth-seeded Guillermo Garcia-Lopez on court one.
Ivanovic advances at China Open
Sixth-seeded Ana Ivanovic beat Casey Dellacqua of Australia, 6-4, 6-0, to advance to the second round of the China Open in Beijing.
Ivanovic was broken twice in the first set, but Dellacqua won less than half the points on her own serve as the Serb wrapped up the victory in little more than an hour.
Madison Keys of United States also advanced by beating Kristina Mladenovic of France, 7-5, 6-2, breaking her opponent five times.
In other first-round matches, 12th-seeded Timea Bacsinszky of Switzerland, Wang Qiang of China, Teliana Pereira of Brazil, and Svetlana Kuznetsova of Russia all advanced.