Romania's Simona Halep fought off big-serving Czech Karolina Pliskova to reach the semi-finals of the Sydney International on Wednesday.
The world number two had earlier been tested in two tight previous matches, and Pliskova again made things difficult for Halep.
Halep had early breaks in both sets only to be pulled back, before the tournament top seed closed out for a 6-4, 7-5 win over the Czech fifth seed in one hour and 38 minutes in blistering heat.
“It was tough today. Was very close. She's playing well, and she's strong with the serve,” Halep said.
“I expected that she's going to hit all the balls, so she did. Against her you don't have rhythm too much, so that's why it's tough to play.”
Halep finished with slightly more winners than Pliskova, 22 to 21, but far fewer errors, 33 to 43.
The Romanian is battling an Achilles injury and admitted to feeling pain during her opening victory over Frenchwoman Caroline Garcia late Tuesday. It followed her late withdrawal from the Brisbane International last week.
Halep will face former world number two Svetlana Kuznetsova in the last four after the Russian fought back from 1-5 down in the opening set to knock out Italian Sara Errani 7-6 (7/1), 6-0.
Halep leads Kuznetsova 3-2 in their previous meetings.
“I know that she's playing a lot of topspin, so it's a different player tomorrow, different style,” Halep said of facing Kuznetsova.
“I expected a tough one. Of course every match at this level is very tough, but I believe I have my chance.”
Elsewhere Puerto Rican qualifier Monica Puig ended Australia's Samantha Stosur's run, 6-4, 6-4 and will face either Swiss eighth seed Belinda Bencic or Russia's Ekaterina Makarova in the semis.
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