Stade Francais showed they have the stomach for a relegation fight by beating Toulon 17-11 in their first game since a player strike, while Brive snatched a 28-25 Top 14 win over Montpellier.
Gonzalo Quesada praised the unity of his Stade players after they downed tools following a sensational announcement that the club planned to merge with Racing 92.
A proposal to join forces with their Paris rivals was soon scrapped and Stade turned their attention back to their bid to avoid the drop, claiming a tense win in a contest which included six yellow cards to go 11 points clear of second-bottom Grenoble.
Both sides had three players sent to the bin, the first of which was Toulon wing Bryan Habana, on a night in which the three-time European champions - who started with Guilhem Guirado and Ma'a Nonu on the bench - were unable to claim their first away victory since last October.
Four Jules Plisson penalties put Stade 12-3 up at half-time and they had a 14-point advantage when Waisea Nayacalevu charged over for the opening try eight minutes into the second half.
Toulon's powerhouse centre Mathieu Bastareaud ploughed his way over for a try which Francois Trinh-Duc converted midway through the second half, but Stade saw out a much-needed win to spark jubilant scenes.
Third-placed Montpellier slipped up, with a last-gasp try from Sevanaia Galala giving Brive a dramatic win.
Brive were also indebted to Gaetan Germain, who scored 23 points with the boot to deny Montpellier after a Bismarck du Plessis try - the visitors' third of the match - five minutes from time looked set to be decisive.