Results of matches played on day four of the Brisbane International at the Queensland Tennis Centre on Thursday (x denotes seed): Round two Jennifer Brady (USA) bt Ashleigh Barty (AUS x1) 6-4, 7-6 (7/4) Karolina Pliskova (CZE x2) bt Ajla Tomljanovic (AUS) 6-4, 6-7 (5/7), 6-1 Petra Kvitova (CZE x5) bt Liudmila Samsonova (RUS) 6-3, 6-2 Naomi Osaka (JPN x3) bt Sofia Kenin (USA) 6-7 (3/7), 6-3, 6-1 Kiki Bertens (NED x6) bt Anett Kontaveit (EST) 6-3, 2-6, 7-5 afp