Alexander Zverev and Grigor Dimitrov were both taken to five sets in their second-round French Open victories.
Germany's Zverev, who is seeded second but yet to advance beyond the fourth round of a Grand Slam, overcame Serbia's world number 60 Dusan Lajovic 2-6 7-5 4-6 6-1 6-2 in Paris.
Fourth seed Dimitrov came through 6-7 (2-7) 6-4 4-6 6-4 10-8 against 21-year-old American Jared Donaldson.
Their match lasted four hours and 19 minutes, and featured 346 points.
Zverev advances to a meeting with Bosnia-Herzegovina's Damir Dzumhur in the third round, while Dimitrov will play Spanish veteran Fernando Verdasco.
Meanwhile, Japan's Kei Nishikori - who is playing in his first Grand Slam since Wimbledon 2017 following a wrist injury - also came through in five sets, seeing off France's Benoit Paire 6-3 2-6 4-6 6-2 6-3.
Seeded 19th, Nishikori's victory takes some revenge for Paire's five-set victory in 2015 US Open.