Unseeded Czech teenager Marketa Vondrousova stunned world number two Simona Halep to reach the quarter-finals at Indian Wells.
The 19-year-old, ranked 61st in the world, beat the Romanian 6-2 3-6 6-2.
Vondrousova has already beaten 2017 French Open champion Jelena Ostapenko and last year's finalist Daria Kasatkina during her run in California.
Meanwhile, Rafael Nadal and Denis Shapovalov reached the fourth round in the men's event.
"I was running a lot - I felt like I was dying for a moment," Vondrousova joked in an on-court interview.
"I'm so happy to be through and so happy with my play.