David Goffin fell to a first-round exit at the Moselle Open in Metz on Tuesday, as Nikoloz Basilashvili received a reprieve courtesy of Zizou Bergs' retirement.
Goffin, who won the event in 2014, fell to a 6-3 6-3 defeat to three-time champion Gilles Simon, who is set to retire at the end of the 2022 campaign.
Simon needed 93 minutes to wrap up his victory over the four-time grand slam quarter-finalist, teeing up a round-of-16 meeting with Italy's Lorenzo Sonego.
"We've known each other for a very long time and I’m always happy to play against [Goffin] one more time before the end," Simon said after the win.
"It was really perfect from the start until the end and that's how I won this one."
Elsewhere, Basilashvili was a set down in his meeting with Bergs when the Belgian qualifier was forced to retire through injury, allowing the fifth seed to progress to a meeting with Arthur Rinderknech.
Rinderknech downed Spain's Jaume Munar in three sets to reach the next round, while Emil Ruusuvuori comfortably saw off Jiri Lehecka 6-4 6-4.