Heavy Polish crowd favorite Agnieszka Radwanska was an easy second-round winner Thursday at the Katowice Open.
The top-seeded former Wimbledon runner-up doused Belgian An-Sophie Mestach 6-3, 6-1 at this indoor hardcourt event.
Radwanska's quarterfinal opponent on Friday will be capable Czech Klara Koukalova.
A Day-4 upset came when Russian lucky loser Elizaveta Kulichkova surprised fifth-seeded Estonian slugger Kaia Kanepi 6-1, 6-2.
Meanwhile, seventh-seeded Belgian Kirsten Flipkens came back to hold off Romanian Monica Niculescu 6-7 (6-8), 6-1, 6-4 and eighth-seeded Slovak Anna Schmiedlova got past Czech Katerina Siniakova 6-1, 3-6, 6-3.
The other quarterfinals will pit second-seeded reigning Katowice champion Alize Cornet against Schmiedlova, third-seeded 2014 runner-up Camila Giorgi versus Kulichkova and Flipkens against Belgian Alison Van Uytvanck. France's Cornet topped the Italian Giorgi in last year's finale at Spodek.