World No 2 Karolina Pliskova has been knocked out of the Australian Open by Russian Anastasia Pavlyuchenkova.

The Czech suffered a 7-6, (7-4), 7-6 (7-3) loss against the 30th seed who had lost their previous six matches. 

Pavlyuchenkova, 28, had a 4-1 lead in the first set, followed by a 2-0 lead in the second before she clinched victory in two hours and 25 minutes. 

Despite hitting six aces and producing only four double faults, Pliskova failed to convert two set points in the second set and then lost a second tie-break to go out. 

Pavlyuchenkova said afterwards: "I'm really happy, but will realise it later because I'm still focusing on the next point.

"I did enjoy the match - to beat Karolina for the first time was amazing.

"I won the Australian junior title twice, it makes me think I can win the senior crown."

She will next play 2016 champion Angelique Kerber who won 6-2, 6-7, (4-7), 6-3 against Camila Giorgi to reach the fourth round. 

Elsewhere, defending Wimbledon champion Simona Halep has earned her spot in the next round after a convincing straight sets win against Kazakhstan's Yulia Putintseva.

The Romanian won 6-1, 6-4 and broke each of Putintseva's service games in the first set before she received a tougher challenge in the second set. 

She will face either Elise Mertens from Belgium or American Catherine Bellis in the fourth round.

Swiss sixth seed Belinda Bencic lost in straight sets 6-0, 6-1 to Estonia's Anett Kontaveit in only 49 minutes. 

She will now face 18 year-old Pole Iga Swiatek in the next round.