Troyes earned a vital win in the battle against the drop as Jean-Christophe Bahebeck's goal, four minutes after coming on, earned victory over relegation rivals Evian.
The 20-year-old on loan from Paris St Germain struck 12 minutes from time, after Brice Dja Djedje had hit a post for Evian, to move Troyes off the foot of the Ligue 1 table.
The hosts are now three points behind their third-bottom opponents and four from safety ahead of Nancy's meeting with Lyon tomorrow.
Evian went into the game on the back of two straight defeats, but they started the better as Troyes goalkeeper Yohann Thuram was called into action early.
Thuram had to block Youssef Adnane's volley from Guillaume Lacour's right-wing cross after two minutes and the same player brought another save out of the keeper following a mazy run toward goal.
Troyes grew into the match and Quentin Othon brought down a Stephane Darbion cross before shooting just wide of a post.
Mohamed Yattara then freed Darbion down the right of the area, but his shot went into the side-netting.
Troyes started the second half where they left off and within a minute Yattara was played through with only Bertrand Laquait to beat, but the keeper won out with an excellent reflex save.
The visitors almost snatched the lead in the 53rd minute when Dja Djedje took a pass from Yannick Sagbo and let fly with a powerful shot which crashed against a post.
If that was a let-off for Troyes, Evian had one of their own in the 66th minute when Benjamin Nivet met a Darbion corner only to see the header stopped on the line by defender Lacour.
But the hosts got a winner in the 78th minute when Nivet released Darbion down the right a he crossed for Bahebeck, who had only been on the pitch four minutes, to fire home.