Richard Cockerill emerged with a 33-23 win from his first match in charge of crisis-hit Toulon on Sunday compounding the misery of Top 14 arch-rivals Toulouse.
Cockerill took over after fellow Englishman Mike Ford quit as head coach this week after Toulon were beaten by Clermont in the European Champions Cup quarter-finals.
"This win is very positive for us," said Cockerill. "The team's spirit was not broken. Our fate is now in our hands."
Toulon are well positioned to qualify for the elite six-team play-offs as they sit fourth with 57 points after overtaking Castres, beaten 17-16 at home by Lyon, on Saturday.
But record 19-time French champions Toulouse slipped to 12th -- six points off the first play-off spot -- and are set to miss the final phase for the first time since 1976.
And their nightmare season continued with France international prop Cyril Baille ruled out for months with ruptured knee tendons.
"This evening we took another knock on the head," said coach Ugo Mola. "To qualify we need to take 15 points and again that might not even be enough.
"The season has been very long, harsh. We've left a lot out there even if this evening I didn't have the impression that Toulouse gave up.
"We have to finish the season well for the players then we have to think about rebuilding."
Toulouse were always on the back foot with Toulon getting a first penalty try after a Maxime Médard knock on after 11 minutes, with Guilhem Guirado touching down the second on 23 minutes.
Paul Perez got a try five minutes later as Toulouse came within four points at the break (17-13). But Toulouse were out of the running after former All Black's Ma'a Nonu powered over to push Toulon 33-16 ahead on 66 minutes.
Leigh Halfpenny accounted for 18 of Toulon's points, with François Trinh-Duc's drop kick rounding off the scores.
- Carter lifts Racing 92 -
Earlier All Black legend Dan Carter helped Racing 92 shade Pau 34-32 to push the defending champions up to sixth.
This was Racing's second successive win in the wake of the aborted merger fiasco with Stade Francais, and it lifted them back into the play-off contention for the first time since before Christmas.
The Parisian outfit were far from happy with the result however.
"It's two points lost," said Racing backs coach Laurent Labit in reference to the attacking and defending bonuses.
"And if we finish level with them at the end of the season Pau will be ahead of us," he lamented.
Racing prop Eddy Ben Arous reflected: "That's the second straight game where we started well but failed to finish off. We have to take it a step further."
Carter, booed off after Racing's defeat last month to leaders La Rochelle, contributed two penalties and converted all four tries from fellow New Zealanders Joe Rokocoko and Ben Tameifuna, Juan Imhoff, and Henry Chavancy.
Racing were coasting 27-8 at the break and heading towards a bonus point but Pau launched a vigorous fightback in the second half, crossing over four times in the closing 20 minutes.
Their fifth and final try came from Daniel Ramsay in the 79th minute.
"I was proud of how they finished, it showed the values that exist at this club, we never let it drop," said Pau head coach Simon Mannix whose side also picked up a defensive bonus point.
La Rochelle edged closer to a semi-final spot Saturday with a 16-5 home win against Bordeaux but rivals Clermont faced increasing pressure from Montpellier after losing 26-21 to Brive.
La Rochelle extended their lead on second-placed Clermont to 14 points and matched Toulouse's unbeaten record of 11 games from the 2009 and 2012 seasons.
But Clermont's shock defeat saw their advantage on third-placed Montpellier, who beat Grenoble 54-14, cut to four points with the top two teams qualifying automatically for the semi-finals.