Seven-time champion Rafael Nadal is out of the Italian Open after a straight-set defeat by Dominic Thiem of Austria in the quarter-finals in Rome.
The Spanish world number four had won all 17 of his matches on clay this year, including against Thiem in the Barcelona Open and Madrid Open finals.
But Thiem, ranked seventh, dominated on Friday, frequently forcing Nadal behind the baseline to set up a 6-4 6-3 win.
He will face world number two Novak Djokovic of Serbia in the semi-finals.
After triumphs in Monte Carlo, Barcelona and Madrid, 30-year-old Nadal was looking to win his fourth straight title on clay this year before the French Open, which starts on 28 May.
However, Thiem could now prove to be a major obstacle as Nadal aims to win a 10th title at Roland Garros.
The 23-year-old Austrian raced into a 5-1 lead with a double break and held his nerve to serve out the first set after Nadal had broken back to make it 5-4.
He continued to thrive by playing closer to the baseline than in recent defeats by Nadal, breaking in the seventh game of the second set.
Thiem then saved break points to hold, before breaking Nadal again to claim only his second win in six meetings with the 14-time Grand Slam champion.