Madrid, Spain: Defending champion Simona Halep lost her first match at the Madrid Open in three years on Thursday as Karolina Pliskova produced an inspired performance to reach the semi-finals.
Halep had won the title here both in 2016 and 2017 but the world number one struggled to impose her baseline game against the power of Pliskova, who won 6-4, 6-3.
Pliskova will now face either two-time Wimbledon champion Petra Kvitova or Russian up-and-comer Daria Kasatkina for a place in Saturday's final.
Meanwhile, Dutchwoman Kiki Bertens continued her impressive week as she backed up a third-round win over world number two Caroline Wozniacki to beat Maria Sharapova in the quarterfinals.
Unseeded Bertens, who reached the French Open semis two years ago, recovered from losing the first set to win 4-6 6-2 6-3 and set up a semi-final with Caroline Garcia who eased past local hopeful Carla Suarez Navarro.
Halep will still be among the favourites later this month at the French Open, where she has twice finished runner-up, but 26 unforced errors marked the Romanian's error-strewn display.
That should take nothing away from Pliskova, whose demon serve and blistering power can take the racket from the hand of any opponent.
After beating Jelena Ostapenko, Anett Kontaveit and Coco Vandeweghe on her way to winning the title in Stuttgart a fortnight ago, Pliskova, the sixth seed, is now the highest-ranked player left in the draw.
The Czech is building up a head of steam for Roland Garros and this latest victory also had a family flavour given Halep had knocked out Pliskova's twin sister Kristyna in the previous round.
A driving forehand down the line clinched the decisive break midway through the first set as Halep spent most of the opening frame pinned behind her own baseline.
There were two more breaks in the second set, the latter confirming Pliskova's comfortable victory as a weary Halep backhand hit the net.