Nicolas Pepe gave the hosts the lead at the Stade Jean-Bouin and they were ahead until the 59th minute when Florentin Pogba – brother of Manchester United’s Paul Pogba – levelled affairs.
Oussama Tannane notched the winner on 77 minutes to leave Les Verts eighth in the Ligue 1 table, with 21 points from 14 games played.
It was Saint-Etienne’s first league victory since the end of October and Galtier hailed the way his charges were able to turn things around to claim the spoils.
“We were slow getting into the game, although there were mitigating circumstances as there were a lot of changes in our team,” he said.
“We gifted them a penalty, didn’t have any rhythm and made a lot of errors. But we managed to stay in the game, or perhaps our opponents missed the opportunity to bury us.
“It was much better in the second half. I’ll take this result with a lot of satisfaction for what the players have done this week to get us back to winning ways, as it had been a while since we won in the league.”
Newcastle United are reportedly ready to start negotiations about making Kenedy's loan move from Chelsea into a permanent deal.
Michy Batshuayi could be facing a lengthy spell on the sidelines after picking up an ankle injury while playing for Borussia Dortmund.
Max Allegri says he is happy at Juventus and has dismissed suggestions he could be leaving the Italian giants this summer.
Ousmane Dembele has pledged his future to Barcelona and says he will not be leaving the Nou Camp in the summer.
Everton hero Tim Cahill believes his former club are 'confused' and have lost their 'identity' as the Toffees fans grow restless.
Ousmane Dembele has shot down rumours linking him with a shock move to Arsenal and says he will not be leaving Barcelona this summer.
Liverpool striker Mohamed Salah says claiming the golden boot is in his mind but winning the Champions League is far more important.
Dele Alli has jumped to the defence of Harry Kane calling his Tottenham team-mate an unbelievable striker and great person.
Ruben Loftus-Cheek says he will wait until Crystal Palace are safe from relegation before deciding on his future.
West Ham boss David Moyes says Marko Arnautovic is finally showing what he can do after switching to an out-and-out striker.