Melbourne - The 2016 Australian Open champion Angelique Kerber lost in three gruelling sets as Russia's Anastasia Pavlyuchenkova reached the quarter-finals for a third time on Monday.
The 30th seed Pavlyuchenkova won through against the German 6-7 (5/7), 7-6 (7/4), 6-2 in 2 hours and 37 minutes to set up a last-eight clash with Garbine Muguruza in Melbourne.
The 28-year-old Pavlyuchenkova has now reached the quarter-finals three times in the last four years - but has never got any further in the Grand Slam.
Results on day eight of the Australian Open Grand Slam at Melbourne Park on Monday (x denotes seeding):
Dominic Thiem (AUT x5) bt Gael Monfils (FRA x10) 6-2, 6-4, 6-4
Stan Wawrinka (SUI x15) bt Daniil Medvedev (RUS x4) 6-2, 2-6, 4-6, 7-6 (7/2), 6-2
Alexander Zverev (GER x7) bt Andrey Rublev (RUS x17) 6-4, 6-4, 6-4
Anett Kontaveit (EST x28) bt Iga Swiatek (POL) 6-7 (4/7), 7-5, 7-5
Simona Halep (ROU x4) bt Elise Mertens (BEL x16) 6-4, 6-4
Garbine Muguruza (ESP) bt Kiki Bertens (NED x9) 6-3, 6-3
Anastasia Pavlyuchenkova (RUS x30) bt Angelique Kerber (GER x17) 6-7 (5/7), 7-6 (7/4), 6-2