Karolina Pliskova became the first major casualty of the French Open on Friday, while Garbine Muguruza ousted Elina Svitolina in a blockbuster third-round clash.
Second seed Pliskova fell 6-3 6-3 to the in-form Petra Martic, who will battle Kaia Kanepi - a 4-6 6-3 6-0 winner against Veronika Kudermetova - for a place in the quarter-finals.
Muguruza kept her hopes of triumphing at Roland Garros for a second time alive by overcoming Svitolina 6-3 6-3, though Sloane Stephens and Anastasija Sevastova found the going much tougher.
Donna Vekic defeated Belinda Bencic 6-4 6-1 and will face Johanna Konta after the Brit defeated Viktoria Kuzmova 6-2 6-1.
Lesia Tsurenko finished off her match with Aleksandra Krunic to book a third-round meeting with reigning champion Simona Halep, while Madison Keys beat Priscilla Hon in another clash held over from Thursday.
PLISKOVA LOSS KEEPS OSAKA AT NO. 1
Four players had a chance to overhaul Naomi Osaka as world number one at the French Open.
After Petra Kvitova and Kiki Bertens pulled out and Angelique Kerber was stunned by Anastasia Potapova, Pliskova was the last of those standing when she stepped out on Court Philippe-Chatrier.
However, the Czech was beaten in straight sets by Martic, who took a 4-1 lead in their head-to-head by continuing her fine run with a 14th win on clay this season - more than any other woman.
Osaka now has one less thing to worry about as she aims to make it three major titles in succession in Paris.
SEVASTOVA DIGS DEEP
Sevastova and Elise Mertens both made major semi-finals in 2018 and they served up an enthralling match to start the action on Court Suzanne-Lenglen.
Mertens passed up five match points in a mammoth third set before Sevastova delivered the crucial break and served out the match to advance to round four.
"I think [my] aggressive play, probably it paid off. And just staying tough. It's not easy when you're always, like, 4-5 down, 5-6 down. It can go either way. In the end, we both didn't deserve to lose," said the victorious Sevastova.
Standing between the Latvian and the quarter-finals is Marketa Vondrousova, who downed Carla Suarez Navarro in straight sets.
NO LET-UP FOR MUGURUZA
Muguruza came from a break down in the second set to triumph against ninth seed Svitolina and reach round four for the sixth year in succession.
However, the 2016 champions faces another tricky challenge in the form of Stephens next.
Stephens, the US Open winner in 2017 and runner-up at Roland Garros last year, beat Polona Hercog 6-3 5-7 6-4 after passing up four match points when serving for the second set on Court Suzanne-Lenglen.
Mugruza said of the American: "I think she's playing good. She did [make the] final last year here, so obviously she likes to play here. She likes the clay court ... it will be another good match."