Chambery sent Ligue 1 side Brest crashing out of the Coupe de France as the amateurs from the fifth division secured penalty shoot-out glory against their lofty opponents.
The minnows from Group D of the CFA2 league thrilled the home support at the Municipal de Chambery stadium, as they followed up a similarly stunning victory over Monaco in the previous round - also on penalties - to book a place in the last 16.
The teams were level at 0-0 after 90 minutes, but when Brest - ninth in the top-flight - went ahead after 107 minutes through Bruno Grougi they looked set to reach the next round.
However Maodo Malick Faye equalised with three minutes remaining and then scored one of Chambery's penalties in their 4-3 shoot-out success, with Larsen Toure and Omar Daf missing for Brest.
Bordeaux were also victims of a major cup upset as they went out to Ligue 2 outfit
Sebastien Renouard scored the only goal at the Stade Jean Bouin, netting in the 65th minute as Jean Tigana's top-flight giants subsided to a team fighting for survival in the second tier.
Nancy of Ligue 1 needed extra-time to get past second division Nimes, with goals from Julien Feret after 67 and 107 minutes earning a 2-1 victory.
Another top-flight team, Lorient, advanced with a 1-0 win over CFA side Fontenay-le-Comte thanks to Mathias Autret's 107th-minute goal.
In matches not involving Ligue 1 sides, Reims beat Clermont Foot 3-1, Drancy won 1-0 at Boulogne, Nantes beat Raon-l'Etape 2-1, Cherbourg lost 1-0 at home to Le Mans, and Martigues defeated Quevilly 5-3 on penalties after a 1-1 draw.
Strasbourg beat Evian 1-0 in the late game, with Ali-Azouz Mathlouthi's 26th-minute penalty for the Championnat National side seeing off the Ligue 2 team who beat Marseille at the last-64 stage.