MONACO (Agencies): Defending champion Stefanos Tsitsipas and third seed Daniil Medvedev have been knocked out of the Monte Carlo Masters in the quarter-finals.
Tsitsipas, 24, lost the opening four games on his way to a 6-2 6-4 defeat by the American eighth seed Taylor Fritz.
Russian Medvedev, 27, was beaten in straight sets 6-3 6-4 by Dane Holger Rune, who is seeded sixth.
Italian Lorenzo Musetti takes on compatriot Jannik Sinner in the remaining last-eight tie on Friday.
Greek Tsitsipas, ranked third in the world, battled back in the second set against Fritz but was eliminated in just over an hour.
Fritz, 25, will face Russian Andrey Rublev in the semi-finals on Saturday.
Second seed Tsitsipas had beaten Fritz in three previous hard-court meetings, and had also recorded 12 victories in total on the Monaco clay, dropping only one set.
He levelled the match at 4-4 in the second set but lost out on his serve again to go behind 5-4, before Fritz sealed the win with an ace on his first match point.
“My level was very high, I played very well,” said Fritz, who becomes the first American to reach the last four in Monte Carlo since Vince Spadea in 2003.
Miami Open champion Medvedev had played for more than three hours on Thursday to take a thrilling 3-6 7-5 7-6 (9-7) win against German Alexander Zverev in the third round.
However, his serve was broken early in both sets by 19-year-old Rune and despite a tight contest in the second set, Rune was able to gain a 5-4 advantage and serve for the match.
“I knew it would be a super-difficult match and that I would have to play at my best level,” said Rune, whose world ranking of ninth is one place higher than fellow semi-finalist Fritz.
In the earlier quarter-final, Rublev secured a 6-1 7-6 (7-5) victory against German qualifier Jan-Lennard Struff. The 25-year-old lost the first game on his serve before winning six in a row in a quick opening set against the world number 100.
But Struff, who defeated fourth seed Casper Ruud in the last 16, forced a tie-break in the second set, in which Rublev regained his composure after a nervous display to win on his second match point.
