Nice crashed out of the Coupe de France after losing to Rennes 7-6 on penalties in a classic encounter on Monday.
The scores were level at 1-1 after 90 minutes and at 2-2 after extra time before it took 18 spot-kicks to settle a thrilling tie which also saw both teams reduced to 10 men.
Claude Puel's Nice, who sit fifth in Ligue 1, have now only won one of their last seven games in all competitions and are out of both cup competitions as their mid-season slump goes on.
The hosts had taken the lead on 39 minutes when Valere Germain's header was tipped away by Benoit Costil, but Alexandre Mendy was on hand to powerfully smash home the rebound with his left foot.
Nice had Vincent Koziello sent off for a second bookable offence with 17 minutes left, but they came so close to killing off the tie moments later. Hatem Ben Arfa astonishingly dribbled past five defenders and the goalkeeper, but Sylvain Armand got back to clear off the goal-line.
That moment proved costly when Rennes equalised with eight minutes of normal time remaining. Moments after Ousmane Dembele had struck the post, a swift break resulted in substitute Jeremie Boga converting Nicolas Janvier's pass, with the goal standing even though he was marginally offside.
An entertaining extra-time period produced chances for both sides and the visitors appeared to have sealed their place in the next round when Janvier set up Benjamin Andre, whose swerving shot deceived Mouez Hassen on 113 minutes.
But a dramatic contest took another twist when Romain Danze was adjudged to have shoved Paul Baysse as he prepared to shoot - earning him a straight red card - and Ben Arfa confidently netted the spot-kick to set up a shoot-out.
Both sides scored five of their first six penalties, with Rennes seeing Juan Quintero's effort saved by the legs of Hassen while Wallyson Mallmann blazed over for the hosts.
It looked like the visitors were going through when Franck Honorat's poor effort was saved by Costil, but Andre then hit the post to further extend the sudden death period.
The two teams had scored six out of eight spot-kicks when the decisive moment finally arrived. Gautier Lloris was denied by Costil, allowing Gelson Fernandes to win it for Rennes, who move into the last 32.
