The Greek Maria Sakkari and US Open semi-finalist Aryna Sabalenka each started the WTA finals in Fort Worth/Texas with a narrow victory.
Fifth-seeded Sakkari won a thriller tiebreak against Jessica Pegula (USA) 7-6 (8-6), 7-6 (7-4). Sabalenka started the group stage with a 3:6, 7:6 (7:5) against the Tunisian Ons Jabeur.
At the WTA finals, after the Grand Slam tournaments the most valuable tennis tournament in terms of points and prize money, two groups of four are initially played. The top two in each group advance to the semi-finals. Germans did not qualify.