Anastasia Pavlyuchenkova shocked three-time Grand Slam winner Angelique Kerber to reach the quarter-finals of the Australian Open.

The Russian beat the 2016 champion 6-7 (5) 7-6 (4) 6-2 in a gruelling encounter that lasted two hours and 41 minutes.

After the pair shared two breaks a piece in the opening set, it was Kerber who managed to get the better of Pavlyuchenkova to take a close tie-break.

Both players served much more effectively in the second set as neither were able to break the other, which lead to another tie-break.

This time it was the underdog who managed to return her German opponent's serve with interest to send the match to a decider.

And as the contest entered its third hour, Pavlyuchenkova was able to break Kerber three times to secure the upset.

The 28 year-old will face two-time Grand Slam champion Garbine Muguruza for a place in the semi-finals after the Spaniard defeated ninth seed Kiki Bertens 6-3 6-3.

Muguruza broke her Dutch counterpart a total of five times to close out the match in just 69 minutes.

And a win for either Muguruza or Pavlyuchenkova would mean they will book their place in a first Australian Open semi-final of their career.