Novak Djokovic was in supreme form once again as he stormed past Karen Khachanov in straight sets to reach the quarter-finals of the 2020 French Open. The top seed, who has looked totally dominant all tournament so far, continued his serene progress with a comfortable win over the 15th seed from Russia. There was a scary moment for the world number one as he – entirely accidentally – struck a line judge with a deflected return of serve, but fortunately the official was okay and the match continued after a quick apology. That was the most alarming moment of the match for Djokovic, who is potentially on course to face Stefanos Tsitsipas in the last four in Paris with Rafael Nadal and Dominic Thiem on the other side of the draw. "It was definitely a closer match than the score indicates," Djokovic told Eurosport. "It was quite even, but I managed to break his resistance towards the end of each set. "Karen was very solid. If you play later in the day with the roof closed thereвЂ™s no bounce at all, so he could pick the ball up with his big weapon вЂ“ the forehand. "I try to be solid mentally in my game all the time, especially in these kind of conditions. You cannot allow yourself to drop focus or go too wild on your shots, because someone like Karen is going to take his chances. "I was 2-3 down in the third facing a couple of break points. Thankfully I played a successful drop shot but my drop shot was not that great today, particularly from the second set onwards. "You just find a way. ItвЂ™s frustrating, for all of us, to slip in a crucial moment, or not make winners you would make in different conditions, but I relied on my legs staying solid and taking my chances when they arose." The Serb won through in just two hours and 23 minutes and will next await Pablo Carreno Busta – a semi-finalist at the US Open last month – in the last eight. Carreno Busta was Djokovic's opponent when he was disqualified at Flushing Meadows for hitting a ball at a line judge; now he could be the one standing between the top seed and the semi-finals in Paris.