Results from matches played on the fifth day of the Brisbane International at the Queensland Tennis Centre on Friday (X denotes seed): Quarter-finals Madison Keys (USA X8) bt Danielle Collins (USA) 6-4, 6-1 Petra Kvitova (CZE X5) bt Jennifer Brady (USA) 6-4, 6-2 Naomi Osaka (JPN X3) bt Kiki Bertens (NED X6) 6-3, 3-6, 6-3 afp