Brisbane - Top-seeded Australian Ashleigh Barty was bundled out of the second round of Brisbane International by American qualifier Jennifer Brady on Thursday.
Barty, playing her first WTA tournament in Australia as the world No 1, made too many unforced errors against an opponent at the top of her game.
Brady recorded her first-ever win over a top 10 player with her 6-4, 7-6 (7/4) win in an hour and a half.
Results of matches played on day four of the Brisbane International
at the Queensland Tennis Centre on Thursday (X denotes seed):
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