PRAGUE (AP) — Defending champion Lucie Safarova withdrew from the Prague Open on Wednesday ahead of her second-round match against Kristyna Pliskova because of illness.

Organizers said she was ill before the tournament and her condition worsened after her 3-6, 7-5, 6-3 victory over Kristina Kucova on Tuesday.

In the quarterfinals, Pliskova will face 144th-ranked Beatriz Haddad Maia. The Brazilian qualifier beat fourth-seeded Samantha Stosur 6-3, 6-2.

Big-hitting Jelena Ostapenko rallied to eliminate second-seeded Caroline Wozniacki 5-7, 6-3, 7-6 (5). The Latvian will play Ana Konjuh next.

Third-seeded Barbora Strycova defeated qualifier Lucie Hradecka 6-3, 7-5 and will meet Katerina Siniakova in the quarterfinals. Siniakova beat Natalia Vikhlyantseva 4-6, 6-4, 6-4.

Camila Giorgi advanced with a 4-6, 6-3, 6-2 victory over Qiang Wang of China. She will next play qualifier Mona Barthel.