Second-division Saint-Etienne edged a 2-1 home win against Metz on Thursday in the first leg of the promotion/relegation play-off that pits the 16th-placed Ligue 1 side against a challenger from the second tier.
Irvin Cardona's late goal gave Saint-Etienne the advantage as they seek a return to the top flight after previously overcoming Rodez in the Ligue 2 play-off.
Malian striker Ibrahim Sissoko had given the home side the lead midway through the first period before Ismael Traore headed top-flight Metz level on the stroke of halftime.
The tie came to life in the 15th minute as the dangerous Georges Mikautadze stood up Saint-Etienne defender Dylan Batubinsika and lashed a fierce left-footed strike against the outside of the post.
But it was the Ligue 2 side who took the lead four minutes later when Sissoko burst onto Mathieu Cafaro's cross and clipped a deft finish over the advancing Alexandre Oukidja for his 14th league goal of the season.
The home side edged the remainder of a tight first half in front of a fervent home support, but in the 45th minute Metz struck back through Traore's powerful header from a corner.
The second half started with both sides going close with efforts from distance but it was again the home side who were the most adventurous.
This willingness to make things happen was rewarded with 10 minutes remaining as Cardona bravely stole in ahead of Oukidja and glanced Cafaro's cross form deep into the unguarded net from 18 yards.
Coach Olivier Dall'Oglio took over the reins at Saint-Etienne in December after his predecessor was sacked following five straight defeats in Ligue 2 with the 10-time champions of France languishing in eighth place in Ligue 2.
He has now brought Saint-Etienne to the brink of a return to the top flight, losing only four matches out of 23, but the most important still remains to be played.
The second leg of the promotion/relegation play-off will take place at Metz's Stade Saint-Symphorien on Sunday.