Roger Federer found a way to beat Germany's Dominik Koepfer in the French Open, despite being far from his best in an unpredictable third-round match.
The Swiss eighth seed lacked fluency and, seemingly, trust in his game before coming through to win 7-6 (7-5) 6-7 (3-7) 7-6 (7-4) 7-5 in Paris.
The 20-time Grand Slam winner clinched victory after three hours and 35 minutes at 00:43 local time.
Federer, 39, will play Italian ninth seed Matteo Berrettini in the last 16.
Berrettini, 25, reached the fourth round at Roland Garros for the first time with a 7-6 (8-6) 6-3 6-4 win over South Korea's Kwon Soon-woo.