Australian Casey Dellacqua lost her opening-round match in straight sets on Wednesday at the Indian Wells tennis tournament in California.
Elena Vesnina of Russia beat Dellacqua 6-4 7-5.
Earlier on Wednesday, Jarmila Gajdosova came from behind to win her first-round match.
She dropped the first set to Coco Vandeweghe of the United States but recovered to post a 4-6 6-3 6-3 win.
It was Gajdosova’s fifth victory from 11 matches this season.
In other first-round results, Timea Bacsinszky of Switzerland defeated Britain’s Anne Keothavong 6-4 2-6 7-5, Kimiko Date-Krumm of Japan downed France’s Pauline Parmentier 6-1 6-3, and Galina Voskoboeva of Kazakhstan beat New Zealand’s Marina Erakovic 5-7 6-3 7-5.
Top-ranked Victoria Azarenka had a first-round bye along with defending champion Caroline Wozniacki.
The men’s draw at Indian Wells begins on Thursday when 16-time grand slam winner Roger Federer will begin his bid for a fourth title in California.