Laura Robson came through an epic contest against seventh seed Peng Shuai to claim her place in the last four of the Guangzhou International Open.
The Briton broke her Chinese opponent three times, including a telling break in game 12, on the way to taking a tight opening set but then lost an equally combative second set to send the match into a decider.
However, Robson registered three more breaks in a more straightforward third set to seal a 7-5 5-7 6-2 victory after three hours on court.
The win continues Robson's remarkable recent success against Chinese opposition, having ousted Li Na in the US Open and second seed Zheng Jie here in Guangzhou.
She will now face third seed Sorana Cirstea in the semi-finals.
The new British number one is aiming to become the first British woman since Jo Durie in 1990 to reach the final of a WTA event, and she is confident she will have recovered from her exertions in time for the clash with Cirstea.
The teenager said: "It's going to be a really tough match because she's a very aggressive player and hits a lot of winners, so I'm going to have to be ready to run a lot, that's for sure.
"I am pretty tired right now but I've had a massage and an ice bath so I'll be fine for tomorrow. It wasn't that hot, it's just incredibly humid here.''
Romanian Cirstea converted four of her eight break-point opportunities to set up a 6-4 6-3 victory over the eighth seed Alize Cornet.
The other semi-final will pit fourth seed Urszula Radwanska against Su-Wei Hsieh.
Radwanska beat Chantelle Scheepers of South Africa 6-1 7-5 in the last eight while Hsieh was a 6-3 6-0 winner over Frenchwoman Mathilde Johansson.