Qualifier Lorenzo Giustino took 6 hours, 5 minutes to beat Frenchman Corentin Moutet in the second-longest match in French Open history.
The Italian won 0-6, 7-6 (7), 7-6 (3), 2-6, 18-16 in a match carried over from Sunday evening. The final set alone lasted three hours.
Only Fabrice Santoro's win against fellow Frenchman Arnaud Clement in 2004 took longer at 6:33.
The French Open is the only one of the four major tournaments which does not use tiebreakers in the final sets to decide men's and women's matches.
Giustino next plays 12th-seeded Diego Schwartzman.