Tsitipas gave the No. 2 Daniil Medvedev, and won against him 6-3, 7-6 (3), 7-5 at Court Philippe Chatrier.
Both won their previous games in straight sets, and both seem to be in a similar vein of rich form going into the quarter-finals.
The Russian wins his match in straight sets to set up a mouth-watering last-eight date with Stefanos Tsitsipas.
Russian second seed Daniil Medvedev was nothing less than spectacular against the 32nd seed Reilly Opelka.
Roger Federer was playing his first match at the French Open since 2015 and he won in the first round.
According to Serbian World No.1 Novak Djokovic, a shift in the favour ATP rankings seems "inevitable".
Both Isner and Garin needed three sets to enter the quarterfinals of the Madrid Open.
As a result, the 25-year-old Russian star, Daniil Medvedev, has withdrawn from the Monte Carlo Masters tournament
Men’s tennis has been dominated by the likes of Novak Djokovic, Roger Federer and Rafael Nadal but some young guns are slowly rising up