Benjamin Corgnet netted an extra-time winner to help Saint-Etienne to a 2-1 win over Ajaccio in Thursday's Coupe de France last-32 encounter.
Christophe Galtier's men started the match in fine fashion and needed only 10 minutes to open the scoring. Jean-Christophe Bahebec beat his marker to the ball after Valentin Eysseric's corner and headed home from close range to make it 1-0.
There were chances for Neal Maupay, Nolan Roux and again Bahebeck in the remainder of the first half, but Riffi Mandanda proved to be too much of obstacle between the sticks.
Saint-Etienne continued to dominate proceedings after the break but failed to add a second goal and were made to pay for their profligacy in the closing stages of regulation time.
Johan Cavalli's free-kick hit the wall before ending up at the feet of Rayan Frikeche and the 24-year-old coolly slotted home to restore parity in the 87th minute.
Neither side seemed able to decide the match in extra time, until Corgnet made the difference in the 120th minute of the encounter.
Saint-Etienne, who required penalties to see off fifth-tier Raon l'Etape to reach this stage, meet Troyes in the round of 16.