Melbourne, Jan 21 (IANS): Taylor Fritz caused a major shock at the Australian Open on Sunday, the American beating last year's runner-up Stefanos Tsitsipas 7-6(7-3), 5-7, 6-3, 6-3 to reach the quarterfinals.

The 12th seed produced brilliant tennis throughout as he wrapped up victory in just over three hours to set up a clash with 10-time champion Novak Djokovic in the last eight.

Fritz struck 50 winners and committed just 19 unforced errors, while Tsitsipas held a 41/33 mark.

The 26-year-old has now advanced to the last eight at three of the four majors, having reached that stage at Wimbledon in 2022 and the US Open in 2023. The six-time tour-level titlist has never advanced to the semifinals at a Slam.

The American holds a 14-7 record at the Australian Open, having earned more wins at the first major of the season than any of the other three.

In other action, Jannik Sinner secured a gritty 6-4, 7-5, 6-3 win straight-sets win over Karen Khachanov to advance to last eight.

Sinner will next play the winner of Andrey Rublev (whom he leads 4-2 in their Lexus ATP Head2Head series) and Alex de Minaur (6-0).

The Italian reached the quarterfinals at Melbourne Park in 2022 and last year fell to Stefanos Tsitsipas in the fourth round. He has reached the quarter-finals or better in five of the past nine majors.

In the women's singles, Barbora Krejcikova ended 16-year-old Mirra Andreeva impressive run with 4-6, 6-3, 6-2 come-from-behind and entered the Australian Open quarterfinals for the second time in her career.

After a come-from-behind win, the Roland-Garros 2021 champion has earned a final eight showdown against defending champion Aryna Sabalenka, who blasted past Amanda Anisimova 6-3, 6-2.

Krejcikova had previously reached the quarterfinals in Australia in 2022 -- and this will be her first appearance in the last eight of a major since then. After winning her first Grand Slam singles title in Paris in 2021, she also reached the quarterfinals of the US Open later that year.