Serena Williams surrendered before Karolina Pliskova on Wednesday in a three sets fight (6-4 4-6 7-5) in Australian Open.
Karolina Pliskova will face Naomi Osaka in the semi-finals. The American great, Serena Williams, had beaten world number one Simona Halep in the fourth round but folded against the big-serving Czech seventh seed, Pliskova who saved four match points before winning under the hot Melbourne sun.
It was a gut-wrenching defeat for the 37-year-old, who tried to comeback in the third set and was leading 5-1 at a stage. But Serena hast to throw it away with some poor serving and wild shots as frustrations bubbled to the surface.
"She was playing very well. Especially at the end of the second set she went for her shots and she was aggressive," said Pliskova. For Pliskova, it is only her third semi-final at a major.
A focused Osaka brutally swept past Ukraine's Svitolina, who was troubled by neck and shoulder problems, in her attempt to win back-to-back Grand Slams.
The Ukrainian needed a similar medical timeout during her third round match, but it was nevertheless a serious statement from the steely-eyed Osaka, who was playing the sort of tennis which drove her to the US Open title. The win ensured she became the first Japanese woman in the final four at Melbourne Park since Kimiko Date in 1994.
Unseeded American Danielle Collins or two-time Wimbledon champion Petra Kvitova play the other semi-final.
Novak Djokovic resumes his quest for a record seventh Australian Open title later against Japanese marathon man Kei Nishikori.
Stefanos Tsitsipas and Rafael Nadal have already secured their berths in the last four.