The world tennis number one Novak Djokovic has reached his 16th consecutive Grand Slam quarter-final while the seven-time champion Rafael Nadal celebrated by his 27th birthday by also reaching the last eight at the French Open.
Top seed Djokovic dropped the first set before prevailing 4-6 6-3 6-4 6-4 over the German Philipp Kohlschreiber, thanks to the 16th seed converting just two of 13 break points
Djokovic's quarter-final opponent will be another German, 35-year-old Tommy Haas, the third oldest male to make the quarter-finals of a French Open.
Nadal, bidding to become the first man to win the same Grand Slam title eight times, trounced the Japanese 13th seed Kei Nishikori 6-4 6-1 6-3.
It was the defending champion's 56th win in 57 career matches at Roland Garros, and his next opponent is the Swiss ninth seed Stanislas Wawrinka, who beat the French seventh seed Richard Gasquet.
If Djokovic and Nadal win, they'll meet in the semi-finals in Paris.