Second seed Karolina Pliskova has been knocked out of the Australian Open in a 7-6 (7-4) 7-6 (7-3) third-round loss to Russian Anastasia Pavlyuchenkova.
Pliskova struggled with her returning game against the 30th seed who had lost their previous six matches.
The 75-minute first set saw only two of the 16 break points converted before Pavlyuchenkova won the tie-break.
Pliskova could not convert two set points in the second set and then lost a second tie-break to go out.
There was another surprise as Swiss sixth seed Belinda Bencic was blown away by Estonia’s Anett Kontaveit, losing 6-0 6-1 in only 49 minutes on Margaret Court Arena.
Kontaveit, the 28th seed, won the first nine games as she completely dominated last year’s US Open semi-finalist.
She will now play 18-year-old Pole Iga Swiatek who defeated 19th seed Donna Vekic of Croatia 7-5 6-3. Prior to Melbourne, the teenager had not been past the second-round stage at a Grand Slam.
Plsikova’s conqueror Pavlyuchenkova, a quarter-finalist last year, joked in her on-court interview: “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.”
Pavlyuchenkova will next play 2016 champion Angelique Kerber, who was made to fight by Camila Giorgi but managed to win 6-2 6-7 (4-7) 6-3.
It was a battle between Giorgi’s aggression and Kerber’s defence with the Italian’s 65 unforced errors key as the German 17th seed went through.
There was no slip-up from Wimbledon champion Simona Halep, who produced an impressive display in her 6-1 6-4 win over Kazakhstan’s Yulia Putintseva.
The Romanian fourth seed broke all of her opponent’s service games in the first set but was given a tougher workout in the second. Having exchanged breaks with Putintseva before breaking again for 4-3, she saved two break points in her next service game.
Halep eventually wrapped up victory in the 10th game when the Kazakh’s slice found the net. She now faces either 16th seed Elise Mertens or American Catherine Bellis.
“It was a great year winning Wimbledon, but here it’s a different tennis,” said Halep, who reached the final in 2018. “I’m ready – I was ready when I got here.”