An outstanding display of goalkicking from Joris Segonds helped Stade Francais to beat Racing 92 35-22 in the Top 14's Parisian derby on Saturday.
Racing scored four tries to Stade's two but the indiscipline of the home side allowed Segonds to nail seven penalties as well as the two conversions for a decisive personal tally of 25 points.
It marked a fifth successive Top 14 defeat for Racing who remain third, eight points behind La Rochelle, but are in danger of slipping up in their bid to finish in the top six and qualify for the play-offs.
"We are in a fight, we must stop calculating, telling ourselves that we are safe," said Racing captain Maxime Machenaud.
"You have to collect the points to stop this downward spiral and qualify (for the play-offs)."
The match had been delayed by Covid from round 21 of the Top 14.
France centre Gael Fickou was due to make his final appearance for Stade Francais in that original game before his move across the city to Racing.
A gentleman's agreement saw him sit this game out, looking on from the stands.
Fickou's old centre partner Jonathan Danty and Racing's veteran Ireland lock Donnacha Ryan both touched down in the first half but the boot of Segonds punished the hosts as Stade turned around with a 19-7 lead.
A try from Les Bleus winger Teddy Thomas and a penalty from Maxime Machenaud early in the second half reduced the gap to four points but further indiscipline gave Segonds further opportunities to rebuild the Stade Francais lead.
The last 10 minutes saw Teddy Iribaren and Thomas again scoring for Racing and Antoine Burban going over for the visitors who climb to eighth in the table, two points behind Castres in the sixth and final play-off place.
Clermont, who are level on points with Racing, will overtake them if they take at least a point from their game against Brive later on Saturday.
Toulon will move into the top six if they beat relegated Agen in Saturday's other 'Covid catch-up' game.