Ostrava WTA results on Thursday (x denotes seeded player): 2nd rd Ons Jabeur (TUN) bt Jelena Ostapenko (LAT) 6-4, 6-4 Elise Mertens (BEL x7) bt Karolina Muchova (CZE) 6-4, 6-2 Aryna Sabalenka (BLR x3) bt Coco Gauff (USA) 1-6, 7-5, 7-6 (7/2) afp