World number two and defending French Open champion Novak Djokovic was beaten by Dominic Thiem 7-6 (5), 6-3, 6-0, while Rafael Nadal cruised to victory after his opponent retired with an injury.
Austria's Dominic Thiem demolished defending champion Novak Djokovic 7-6 (5), 6-3, 6-0 in a stunning French Open upset on Wednesday, setting up a semifinal duel against nine-time champion Rafael Nadal.
Sixth seed Thiem sent the world number two crashing to his earliest loss in Paris in seven years.
Nadal barely broke a sweat to reach his tenth Roland Garros semifinal when Spanish compatriot Pablo Carreno Busta retired in the second set through injury.
Nadal, also bidding for a tenth title at Roland Garros, was leading 6-2 2-0 when Busta decided he could not continue after receiving lengthy treatment for a left abdominal muscle injury at the end of the first set.
The 31-year-old Nadal has spent only around eight hours on court, dropping 22 games in the process, to reach his record-extending tenth semifinal at the French Open.
It is the fewest number of games Nadal has lost on his way to the last four on the Paris clay.
In 2008, he dropped 25.
World number three Karolina Pliskova reached the French Open semifinals with a 7-6(3) 6-4 victory against Caroline Garcia, ending the French presence in the main draw.
The second-seeded Czech, who had never got past the second round here before, mastered windy conditions to set up a meeting with either Romania's Simona Halep or Ukraine's Elina Svitolina.
Relying on her powerful serve and groundstrokes, the 25-year-old Pliskova also benefitted from 28th seed Garcia's numerous unforced errors.
She sealed the victory in a tight contest on her first match point with a forehand winner down the line.
Former French Open runner-up Simona Halep staged a remarkable fightback and saved a match point to reached the semifinals with a 3-6 7-6(6) 6-0 win over Elina Svitolina.
Romanian third seed Halep trailed by a set and 5-1 against the fifth seed but somehow dug herself out of a hole before storming to victory.
Ukrainian Svitolina saved four set points at 5-6 in the second and then had a match point in the tiebreak which Halep saved with a brave backhand winner that kissed the sideline.
Halep clinched the second set with a forehand winner and swept through the decider as Svitolina's spirit sagged, sealing victory with an ace.
Halep will play second-seeded Czech Karolina Pliskova in the semifinals, while in the other half of the draw Latvian teenager Jelena Ostapenko will take on Swiss Timea Bacsinszky.
All four players are seeking a first grand slam title.
Quarterfinal results (Wednesday)
Andy Murray (Britain) beat Kei Nishikori (Japan) 2-6 6-1 7-6(0)
Stan Wawrinka (Switzerland) beat Marin Cilic (Croatia) 6-3 6-3 6-1
Dominic Thiem (Austria) beat Novak Djokovic (Serbia) 7-6 (5), 6-3, 6-0
Rafa Nadal (Spain) beat Pablo Carreno Busta (Spain) 6-2 2-0 (Retired)
Simona Halep (Romania) beat Elina Svitolina (Ukraine) 3-6 7-6(6) 6-0
Karolina Pliskova (Czech Republic) beat Caroline Garcia (France) 7-6(3) 6-4