US Quevilly have shocked Ligue 1 side Rennes by battling back from a goal down to reach the final of the Coupe de France.
The third-tier minnows, who dumped Marseille out in the last round, found themselves behind early on thanks to Julien Feret's eighth-minute strike.
Yann M'Vila's long-range effort struck the post and Feret reacted quickest to tap the ball into an empty net.
Substitute Karim Herouat's shot from the edge of the box found the top corner to draw the home side level in the 64th minute and restore hope of booking a fairytale final against Lyon.
Their dreams came true deep into injury time, when Anthony Laup stretched to poke the ball past Benoit Costil and record a famous victory for the Championnat National side with 93 minutes on the clock.
The final will take place at the Stade de France on April 28.