The eighth seed joined Novak Djokovic and Rafael Nadal, who had much easier days in beating Ricardas Berankis and Cameron Norrie, respectively – the latter's defeat ending British singles hopes for the tournament.
Another leading seed fell in the women's event in the shape of Elina Svitolina but defending champion Iga Swiatek and fourth seed Sofia Kenin both won, as did 17-year-old Coco Gauff.
Picture of the day
Shot of the day
Take a bow Lorenzo Musetti.
Norrie's all white
Norrie has lots of reasons to remember the clay-court swing fondly but there is one reason why the British number two is happy to leave the red stuff behind.
"I'm looking forward to at least going to practise and there's not clay all over my bag and there's clay everywhere," he said. "I'll be looking forward to getting on the grass and being in the whites and being clean."
Halep back on court
Saturday brought a positive update from a player much missed at Roland Garros – Simona Halep. The Romanian has been out of action since tearing a calf muscle last month and has three weeks to try to get ready to defend her title at Wimbledon.
Women: Elina Svitolina (5), Jennifer Brady (13), Elise Mertens (14), Karolina Muchova (18), Jessica Pegula (28), Kontaveit (30)
Who's up next?
Serena Williams continues her bid for a 24th grand slam singles title with a fourth-round clash against young Kazakh Elena Rybakina on Sunday.
Daniil Medvedev faces a big test of his new-found affinity for the red stuff against clay-court specialist Cristian Garin while Stefanos Tsitsipas meets reliable Spaniard Pablo Carreno Busta.
Victoria Azarenka opens proceedings on Court Philippe Chatrier against Anastasia Pavlyuchenkova, with Alexander Zverev and Kei Nishikori given night-time duties.