GSTAAD, Switzerland (AP) Top-seeded Caroline Garcia of France was beaten by 140th-ranked Tereza Martincova 7-5, 7-6 (1) in the second round of the Gstaad Ladies Championship on Thursday.
Although the 22-year-old Czech player had no aces - compared to 11 for 20th-ranked Garcia - she was strong on her second serve.
Martincova dropped serve when leading 5-3 in the second set before racing to victory in the tiebreaker.
Second-seeded Kiki Bertens of the Netherlands is through to the quarterfinals of the clay-court event in the Swiss Alps after easing to a 6-4, 6-2 second-round win against qualifier Anna Zaja of Germany.
She next plays fifth-seeded Johanna Larsson of Sweden, who won 1-6, 7-5, 6-1 against Barbara Haas of Austria.