MELBOURNE, AUSTRALIA - JANUARY 23: Barbora Strycova of the Czech Republic plays a backhand in her third round match against Garbine Muguruza of Spain during day six of the 2016 Australian Open at Melbourne Park on January 23, 2016 in Melbourne, Australia. (Photo by Mark Kolbe/Getty Images)

Two more top 10 seeds have been knocked out of the Australian Open, as day six saw No.3 seed Garbiñe Muguruza and No.9 seed Karolina Pliskova both lose.

Muguruza was upset by world No. 48 Barbora Strycova, 6-3, 6-2 in just over an hour.

Seventh seed Angelique Kerber is now the highest ranked seed in the bottom half of the draw, as the 2016 Australian Open has seen the top seeds in the women's draw dropping like flies in the first few rounds.

It is only the second time Strycova has reached the fourth round of a Grand Slam in 39 attempts.

She will now face two-time Australian Open champion Viktoria Azarenka in the round of 16, after she easily accounted for 18-year-old Naomi Osaka 6-1, 6-1 on Saturday.

No.9 seed Karolina Pliskova was also knocked out, as she went down 6-3, 6-2 to Russian 21st seed Ekaterina Makarova.

Makarova will face Great Britain Johanna Kunta in the fourth round, after her 6-2, 6-2 win over Denisa Allertova.