World number eight Angelique Kerber defeated Venus Williams to reach the semi-finals at Indian Wells.
The 31-year-old German clinched her third semi-final in the event with a 7-6 (7-3) 6-3 win over American Williams in one hour 36 minutes.
In the men's singles, Frenchman Gael Monfils was forced to withdraw from his quarter-final against Dominic Thiem after suffering an Achilles injury.
Austria's Thiem, 25, will face Canada's Milos Raonic in Saturday's semi-final.
Raonic dominated Serbian teenager Miomir Kecmanovic 6-3 6-4 following 13 aces to reach his second consecutive Indian Wells semi-final.
Kerber, a three-time Grand Slam winner, triumphed in the first set thanks to a dramatic tie-break that featured four breaks of serve.
In the semi-final, she will face in-form Belinda Bencic of Switzerland, who reached the semis after a 12-match winning streak including a quarter-final win over Karolína Plískova.
"Venus is just such a great player and an amazing champion," Kerber said about her opponent, who came on to the court with a heavily taped right knee.
"It's always an honour to share the court with her. She's still playing at such a high level."
World number seven Thiem advanced to his first semi-finals at Indian Wells without hitting a ball after Monfils' withdrawal. He previously reached the quarters in 2017.
"I tried to warm up and my left Achilles was very painful for a couple days," Monfils told the crowd.
"And this morning, it was really tough for me to run at 100%, and tonight I tried to hit a little bit and I cannot compete 100% tonight.
"I'm so sorry, guys, to put you in this situation, and I so thank you for everything you gave me this week and, again, I'm sorry."
Elsewhere, Canadian Bianca Andreescu and Elina Svitolina of Ukraine play in the other semi-final on Saturday.
Roger Federer and Rafael Nadal will be vying to set up a blockbuster semi-final when they play in the remaining two quarter-finals on Friday.