Despite a narrow defeat at home against Ampuis (18-19), Stade Niçois qualified for the round of 16 thanks to their victory in the first leg (17-14).
Nice will face another team from pool 10, Martigues, who has just eliminated Saint-Etienne, in the next round.
The winner of this match will secure a spot for promotion.
The first leg is scheduled for next Sunday in Bouches du Rhône and a second leg in Nice on Sunday, May 25.
The reserve team won in the 8th finals against Berre 18 to 14. The Niçois will compete in the quarterfinals against Côte Vermeille next weekend.