MADRID: Top-ranked Simona Halep lost to Karolina Pliskova 6-4, 6-3 in the Madrid Open quarterfinals on Thursday.
Halep was the two-time defending champion and on a 15-match winning streak at the clay-court tournament.
But Pliskova gave the Romanian no chance, breaking her serve four times and hitting 20 winners.
"This was one of my best matches of the year," the sixth-seeded Pliskova said. "I feel amazing since in the last six matches I lost to her. I never thought I would beat her. My serve was great and everything went my way."
Pliskova's only prior victory from a previous seven matches against Halep was in the 2016 Fed Cup.
Pliskova won her 10th career title in April, when the Czech was victorious on clay in Stuttgart.
She will play Petra Kvitova or Daria Kasatkina in the semifinals.
Seventh-seeded Caroline Garcia also advanced to the final four after beating Carla Suarez Navarro 6-2, 6-3.
On the men's side, Kyle Edmund continued his excellent run in Spain by ousting eighth-seeded David Goffin 6-4, 6-4 in the third round. Edmund, an unseeded Brit, defeated former No. 1 Novak Djokovic in straight sets on Wednesday.
Denis Shapovalov also defeated Milos Raonic 6-4, 6-4 in an all-Canadian clash.
