Paris - German fifth seed Alexander Zverev reached his second successive Roland Garros quarter-final on Monday with a 3-6, 6-2, 6-2, 7-6 (7/5) win over Italy's Fabio Fognini.
Zverev will face top seed and world number one Novak Djokovic for a place in the semi-finals.
Last year he achieved his best run at the Slams, making the quarter-finals where he was defeated by eventual runner-up Dominic Thiem.
"Fabio is playing the best tennis of his life," said Zverev of the 32-year-old Italian who won his first Masters title on the clay of Monte Carlo in the run-up to Paris.
"So I am happy to get through this and into another quarter-final here."
Zverev is 2-2 against Djokovic in his career but won their only meeting on clay in the Italian Open final in 2017 in straight sets.
Fognini, the ninth seed, hit 53 unforced errors as his game fell to pieces after a promising opening set.
Results from the ninth day of the French Open on Monday (x denotes seeding):
Men
4th round
Novak Djokovic (SRB x1) bt Jan-Lennard Struff (GER) 6-3, 6-2, 6-2
Alexander Zverev (GER x5) bt Fabio Fognini (ITA x9) 3-6, 6-2, 6-2, 7-6 (7/5)
Dominic Thiem (AUT x4) bt Gael Monfils (FRA x14) 6-4, 6-4, 6-2
Karen Khachanov (RUS x10) bt Juan Martín Del Potro (ARG x8) 7-5, 6-3, 3-6, 6-3
Kei Nishikori (JPN x7) bt Benoît Paire (FRA) 6-2, 6-7 (8/10), 6-2, 6-7 (8/10), 7-5
Women
4th round
Madison Keys (USA x14) bt Katerina Siniakova (CZE) 6-2, 6-4
Ashleigh Barty (AUS x8) bt Sofia Kenin (USA) 6-3, 3-6, 6-0
Simona Halep (ROM x3) bt Iga Swiatek (POL) 6-1, 6-0
Amanda Anisimova (USA) bt Aliona Bolsova (ESP) 6-3, 6-0