Girondins Bordeaux reached the French League Cup final with a 3-0 away thrashing of Paris St Germain on Wednesday.
Bordeaux, who are second in Ligue 1, will be the hot favourites for the April 25 final at the Stade de France against Vannes after the Ligue 2 side knocked out Nice on penalties following a 1-1 draw.
However, the Aquitaine side, who thrashed PSG 4-0 in Ligue 1 last month, will take nothing for granted bearing in mind that the last non-first division team to reach the final, Gueugnon, beat PSG in 2000.
At the Parc des Princes, Bordeaux were clearly the better side and their domination was rewarded in the 17th minute when former Manchester United striker David Bellion headed home from a Franck Jurietti cross.
Defender Souleymane Diawara put the result beyond doubt three minutes from time when he met a Jussie cross to lob PSG keeper Mickael Landreau.
In added time, Brazilian midfielder Wendel completed the rout from close range after being set up by compatriot Fernando.
Vannes, who only turned professional when they were promoted from the third division last season, went ahead on the hour when midfielder Seidi Khiter poked the ball home after a swift counter-attack.
The Brittany side seemed on course to complete an upset until two minutes from time when Tunisia forward Chaouki Ben Saada, on as a 64th minute substitute, sent the tie into extra time with a powerful drive from inside the box.
Vannes goalkeeper Christophe Revel kept the Nice strikers at bay in extra time and was decisive in the shootout, saving Loic Remy's penalty before watching Cyril Rool's hit the bar.