Results from the WTA clay-court tournament in Stuttgart on Wednesday (x denotes seeding): 2nd rd Ashleigh Barty (AUS x1) bt Laura Siegemund (GER) 6-0, 7-5 Anett Kontaveit (EST) bt Sofia Kenin (USA x3) 7-5, 6-4 Petra Kvitova (CZE x7) bt Maria Sakkari (GRE) 6-3, 3-6, 6-3 1st rd Jelena Ostapenko (LAT) bt Stefanie Voegele (SUI) 6-4, 7-5 Karolina Pliskova (CZE x6) bt Tamara Korpatsch (GER) 7-5, 3-6, 6-3 Angelique Kerber (GER) bt Ekaterine Gorgodze (GEO) 6-2, 6-2 Marketa Vondrousova (CZE) bt Marie Bouzkova (CZE) 6-1, 7-6 (8/6) afp