Top-seeded Aryna Sabalenka won for the first time since late February, outlasting American Alison Riske 7-6 (3), 6-4 on Wednesday to start the weather-delayed Credit One Charleston Open.
Sabalenka, of Belarus, had lost her opening matches at Indian Wells and Miami after falling to new No 1 Iga Swiatek in quarterfinals at Qatar six weeks ago.
Still, Sabalenka needed nearly two hours to make it past Riske. Sabalenka led 5-3 in the opening set before Riske forced a tiebreaker. Sabalenka eventually pulled away and won five of the final six points in the tiebreak.
Other seeded winners including No 3 Karolina Pliskova, No 6 Jessica Pegula, No 9 Madison Keys, No 10 Belinda Bencic and No 12 Alize Cornet.
Pliskova of the Czech Republic topped Katarina Zavatska of Ukraine 5-7, 7-5, 6-4. American Pegula ousted Italian Jasmine Paolini 6-2, 6-1, and Keys of the United States beat Norway's Ulrikke Eikeri 6-3, 6-1.
Bencic, who won Olympic Gold in Tokyo, defeated Linda Fruhvirtova of the Czech Republic 6-1, 7-6 (6). Cornet of France bested American Hailey Baptiste 6-3, 6-2.
The season's first clay-court event had a full schedule after several of Tuesday's matches were wiped out due to rain and severe weather in the area.