Karolina Pliskova came out on top against Simona Halep to book her place in the semi-finals of the WTA Finals in Shenzhen.
It was a match the ebbed and flowed, but the world number two eventually came out on top with a 6-0, 2-6, 6-4 success.
Czech Pliskova will now face Ashleigh Barty of Australia in the last four.
Earlier, defending champion Elina Svitolina ensured she remained unbeaten in the group stage after dispatching alternate Sofia Kenin of the United States.
The eighth seed had already been assured of a place in the semi-finals but she still battled hard for a 7-5 7-6 (10) win in two hours and 10 minutes.
Svitolina told the WTA: “Each time I step on the court I have to win.
“My parents raised me this way – that I have to fight for everything, I have to give 100 per cent each time I play.”
Svitolina will face seventh seed Belinda Bencic for a place in the final.
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