Collated results Saturday from the WTA Gippsland Trophy, Yarra Valley Classic and Grampians Trophy at Melbourne Park: Yarra Valley Classic Semi-finals Ashleigh Barty (AUS x1) bt Serena Williams (USA x5) walkover Garbine Muguruza (ESP x6) bt Marketa Vondrousova (CZE x8) 6-1, 6-0 Gippsland Trophy Semi-finals Kaia Kanepi (EST) bt Ekaterina Alexandrova (RUS x9) 6-3, 7-6 (8/6) Elise Mertens (BEL x7) bt Naomi Osaka (JPN x2) walkover Grampians Trophy Quarter-finals Maria Sakkari (GRE x5) bt Angelique Kerber (GER x8) 6-4, 6-2 Anett Kontaveit (EST x6) bt Victoria Azarenka (BLR x3) walkover Jennifer Brady (USA x7) bt Barbora Krejcikova (CZE) 7-6 (7/5), 6-4 Ann Li (USA) bt Sorana Cirstea (ROU) 6-3, 6-1 mp/th