Sloane Stephens dropped to 3-4 since the U.S. Open after her 6-3, 6-2 loss to Tunisian qualifier Ons Jabeur.
MOSCOW — Sloane Stephens and Karolina Pliskova were both eliminated from the Kremlin Cup on Wednesday, with the latter result ensuring that Elina Svitolina has qualified for the WTA Finals.
The fifth-ranked Pliskova lost to Russian veteran Vera Zvonareva 6-1, 6-2, holding serve only once in the match.
Because of the loss, Svitolina will play in the season-ending WTA Finals in Singapore. Pliskova can still qualify, but she could also be overtaken by Kiki Bertens.
The 34-year-old Zvonareva, a former Wimbledon and U.S. Open finalist, will next face Anastasija Sevastova in the quarterfinals. The Latvian beat Yulia Putintseva 7-5, 4-6, 6-4.
Stephens lost to Tunisian qualifier Ons Jabeur 6-3, 6-2. The third-seeded American, who had a first-round bye, lost her opening service games in each set.
Stephens, the 2017 U.S. Open champion, secured qualification for the WTA Finals last week after a strong season which included reaching the French Open final.
Jabeur will next face Anett Kontaveit in the quarterfinals. The eighth-seeded Estonian beat Kristina Mladenovic 6-2, 7-6 (3).
In the men's draw, Ricardas Berankis beat Aljaz Bedene 3-6, 7-6 (3), 7-6 (5) to reach the quarterfinals.