Novak Djokovic of Serbia crashed out of the Monte-Carlo Masters after losing to Russia's Daniil Medvedev in the quarter-final.
World number one Djokovic was condemned to a 6-3, 4-6, 6-2 defeat at Monte-Carlo Country Club.
Medvedev, ranked at 14th in the world, has reached his first Association of Tennis Professionals (ATP) Masters 1000 semi-final.
"It's definitely the best match of my career," said Medvedev.
"Not in terms of the level of tennis, but definitely the result.
"It's just amazing."
Medvedev will meet Serbia's Dušan Lajović, who recorded a 6-4, 7-5 victory against Italy's Lorenzo Sonego.
Rafael Nadal continued his bid for his 12th Monte-Carlo Masters title, beating Argentina's Guido Pella 7-6, 6-3.
The Spaniard is the defending champion and also won in 2017 and 2016.
He will now play Croatia's Borna Ćorić, who came back from one set down to win 1-6, 6-3, 6-2.