Les Verts are currently fourth, just three points behind Olympique Lyonnais, who occupy the third and final UEFA Champions League place, after a fine run which has seen them win three of their last four Ligue 1 Conforama games, drawing the other.
How did Sainté saunter back into European contention? ligue1.com takes a look…
ASSE came close to continental glory back in 1976, when they were edged 1-0 by Bayern Munich in the European Cup final at Glasgow's Hampden Park. The 10-time French champions also made the competition's semi-finals the season before, and the quarters in the campaign after, but they have yet to make the knock-out stages since.
Their most recent success of any kind was a Coupe de la Ligue triumph in 2013, and although club captain Loïc Perrin and talismanic goalkeeper Stéphane Ruffier remain regulars from that team, Jean-Louis Gasset's recent rebuilding job should not be understated.
Gasset took the reins in December 2017, a month after Oscar Garcia had been dismissed following a 5-0 loss to Derby du Rhône rivals Olympique Lyonnais, and although Sainté then went 13 games undefeated, their seventh-place finish was still some 23 points behind Lyon, who finished third, and few expected Gasset's first full season to result in too much beyond top-flight stability.
Not that the Stade Geoffroy-Guichard was shorn of exciting arrivals last summer: attacking midfielders Wahbi Khazri and Rémy Cabella signed from Sunderland and Olympique de Marseille respectively, while former Sevilla defender Timothée Kolodziejczak was tempted back to French football on loan from Mexican side, Tigres.
The new-look ASSE took a while to get going, though. An opening-day 2-1 win over EA Guingamp was followed by four games without a win, and just a single goal scored. Something had to give, and the first glimmer of Gasset's tactical nous was just around the corner.
Khazri had been an attacking midfielder his whole career, a maker rather than a taker, a player who had never scored double figures in a league season. But Gasset saw something in the diminutive Tunisian that others had missed, and started putting him at the point of his attack in his favoured 4-2-3-1 system.
A month later Khazri scored a brace in a 2-0 win over AS Monaco - the third and fourth strikes of a now 13-goal season - and Gasset was beginning to feel vindicated.
"I said that our game was improving and we've just played a really good game," he said. "We didn't concede and Ruffier was phenomenal. Everyone was getting concerned but I knew we needed time. In seven days, we've taken nine points and we're back near the top of the league."
Khazri alone is not the only reason they have stayed there. Neven Subotic has formed a quick understanding with Perrin at centre-back; new boys Cabella and Kolodziejczak have started more games than any outfield player not called Yann M'Vila; and when Kévin Monnet-Paquet suffered cruciate ligament damage in February, last winter's acquisition Mathieu Debuchy was ready to step into the breach.
Where Khazri had been a midfielder facing third-tier English football with Sunderland, Debuchy had spent much of the four years before joining Saint-Etienne in Arsenal's reserves, the former France right-back turning out just 13 times for the Gunners between 2014 and '18.
Now 33, it almost looks as if the Debuchy that so impressed at LOSC and Newcastle earlier in his career had been frozen in time in London. Three years Monnet-Paquet's senior, Debuchy has still played fewer minutes this season, yet covered more ground, suffered more fouls (13 vs. 11), and produced four goals and two assists, to his recent predecessor's one each in both columns.
With a brace in Sainté's 3-0 win over Girondins de Bordeaux last Sunday, the right-back has now scored eight league goals since he arrived in the Auvergne-Rhône-Alpes region. Only Real Madrid captain Sergio Ramos, with 10, has scored more goals than Debuchy in that time among defenders in Europe's top five leagues per UEFA coefficient.
"The players showed great spirit, led by Mathieu Debuchy," enthused Gasset at his post-match press conference. "I saw him limping and suffering, and then he came back on and scored twice. People like him are why we do this job."
Where Saint-Etienne have won three of their last four, Lyon have lost two of their last three, meaning the gap to third this season is just three points with six games left to play. It is a far cry from the 23-point cushion OL enjoyed last term.
Momentum on their side?
Paris Saint-Germain have run away with the title, despite a recent stutter; LOSC are red-hot favourites to join them in automatic qualification for next season's Champions League, but as for the rest?
"There are still 18 points up for grabs," warned Gasset. "And if we keep playing like that we'll progress. Let's see where we are after that."
With Gasset's guidance and Khazri's and Debuchy's stars shining brighter than ever, perhaps the safe money is on Les Verts completing the podium come May. It would be equal parts deserved and overdue for fans of one of French football's crown jewels, top of the world game yesterday, halfway back towards the summit today.