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 2hrs 37mins 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. pst/th