Petra Kvitova established herself as a leading contender for the French Open title after defeating China's Zhang Shuai to reach the quarter-finals.
Two-time Wimbledon champion Kvitova was rarely troubled by the world No 39 aside from being broken when she served for the match at 5-2 in the second set but eventually sealed a 6-2 6-4 victory.
Kvitova, who is one of just two Grand Slam champions left in the field alongside Australian Open winner Sofia Kenin, is through to the last eight at Roland Garros for the first time since 2012, without losing a set.
The 30-year-old Czech made the perfect start on Court Philippe Chatrier when she raced into a double break lead as she seized control of the contest to claim the first set.
Kvitova, seeded seventh, broke in the first game of the second set as well, but some unforced errors at 5-2 allowed Zhang to win successive games before the world No 11 sealed victory with a love service hold.
The Czech will next face Germany's Laura Siegemund after the world No 66 defeated Spain's Paula Badosa, who had beaten Grand Slam winners Jelena Ostapenko and Sloane Stephens in her previous two matches, 7-5 6-2.
Kenin beats home hope Ferro
Meanwhile, fourth seed Kenin recovered from a set down to beat France's Fiona Ferro 2-6 6-2 6-1.
Home hope Ferro, playing in the fourth round of a Grand Slam for the first time and on an eight-match winning run, recovered from losing her opening service game to win six games in a row to claim the first set.
Kenin, world No 6, broke Ferro three times consecutively to the level the match and subdue the vocal French crowd inside Court Philippe Chatrier.
The American maintained her ascendency in the second set to open a double break advantage and she was able to seal victory with a backhand winner on her first match point.
She will next play either Tunisia's 30th seed Ons Jabeur or American Danielle Collins, who will begin their fourth round match on Tuesday after they were unable to play following a lengthy rain delay.
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