Elena Vesnina recovered after blowing three match points to beat Venus Williams 6-2 4-6 6-3 and reach the semi-finals of the WTA event in Indian Wells.
Russian Vesnina staved off six break points in the last game of the match, closing out the match with two forehand winners.
Williams overcame three match points in the eighth game of the third set, which featured six deuces and lasted nine minutes.
No.14 seed Vesnina will face No.28 seed Kristina Mladenovic in the semi-finals.
"Kristina is on fire and so am I and I think it is going to be a great match," Vesnina said on BT Sport 1.
"It's our first time in a semi-final of such a great event so it is a big chance for both of us."
Frenchwoman Mladenovic beat Caroline Wozniacki 3-6 7-6 (7-4) 6-2 to break into the top 20 in the WTA Tour rankings for the first time in her career.
"I see that it's paying off, that the results are coming," Mladenovic said. "The ranking is just the consequence of all the work you put on a daily basis.
"Eventually, you're playing those great matches better and better and give yourself a chance to win them, and then the ranking obviously follows."
It is the first time 23-year-old Mladenovic has reached the last four at a tournament of this standing.
"I'm just super satisfied that I am on that kind of stages right now and trying to use my chances and the my opportunities I have," Mladenovic said.
In the other semi-final, No.3 seed Karolina Pliskova of the Czech Republic will take on two-time major winner Svetlana Kuznetsova of Russia.
