England's Laura Massaro saved four match balls as she beat Low Wee Wern to reach the semi-finals of the squash World Championship in Malaysia.
Massaro, the world number two, came back from the brink of defeat in game four to beat the Malaysian 12-14 11-6 6-11 13-11 11-7 in 105 minutes.
"I'm really proud of that match tonight, I gave it everything," said the 30-year-old from Preston.
Seven-time champion Nicol David beat Camille Serme 9-11 11-5 11-5 6-11 11-4.
The Malaysian superstar has not lost a World Championship match since 2007 and had a 12-0 career record against Serme, but the Frenchwoman put up a spirited display before David dominated the decider.
"These sort of matches actually get me going, so I will get adequate rest and be fresh for tomorrow," said the 30-year-old world number one.
At one hour and 45 minutes, Massaro's match against Wee Wern was the longest of her career and the second longest match in the 35-year history of the World Championship.
"This was definitely Wee Wern's best showing against me as she put me under so much pressure," said Massaro.
"It's a sign of how much she's improved - but I'm proud of myself for pulling through."
Top seeds David and Massaro remain on course for a repeat of last year's final, but Massaro must again get past Egyptian third seed Raneem El Weleily in the last four.
David takes on another Egyptian, Nour El Sherbini, in Saturday's other semi-final.