St Etienne confirmed their resurgence under coach Claude Puel when a Denis Bouanga second-half goal earned them a 1-0 home victory against Monaco in Ligue 1 on Sunday.
Bouanga struck shortly before the hour to give Les Verts their third victory in four league games since former Southampton and Leicester City boss Puel took over four weeks ago.
The result lifted St Etienne up to eighth in the standings on 18 points from 12 games, nine behind leaders Paris St Germain but only two adrift of second-placed Angers.
Monaco, who finished with 10 men after Ruben Aguilar was sent off two minutes into added time, dropped to 15th on 15 points.
Elsewhere, Nantes suffered their third consecutive defeat in Ligue 1 when they were beaten 2-0 at Girondins de Bordeaux, slipping down to third on 19 points.
At Geoffroy Guichard, St Etienne seemed content to abandon possession to their visitors, hoping to hit Monaco on the break while their back four handled the Wissam Ben Yedder threat perfectly.
St Etienne, now unbeaten in five games in all competitions with Puel, could have doubled the tally in injury time but Bouanga was brought down by Aguilar while rushing towards goal, resulting in the defender being shown a straight red card.