Maria Sharapova follows Serena Williams in crashing out of the Australian Open in the fourth round
Dominka Cibulkova booked her place in the Australian Open quarter-finals with a comeback victory over Maria Sharapova
By Tim Clement - Twitter: @SkyTimClement
Last Updated: 20/01/14 4:29pm
Hampered by a hip problem, third seed Sharapova was well below par as she made 45 unforced errors, served eight double-faults and was broken seven times.
The victory sees 20th seed Cibulkova make the quarter-finals at Melbourne Park for the first time, with Simona Halep up next.
"I was 100 per cent sure I could win," said Cibulkova.
"I never doubted myself even when I lost the first set. I knew what I needed to do. The most important thing is to believe in yourself."
Sharapova, who had won three of their previous five meetings, looked on course for victory as she broke three times to take the first set.
However, the Slovakian won five successive games at the start of the second before serving it out at the third time of asking, with Sharapova making 15 unforced errors to just five winners.
After Sharapova took a medical timeout as she struggled with a hip problem, Cibulkova reaped the rewards of seven double-faults from the 2008 champion in the decider, breaking for a third time on her second match point to progress.
Halep, the 11th seed, secured her progress into the last eight with a 6-4 2-6 6-0 victory over No 8-ranked Jelena Jankovic.