Champions Racing 92 put their off-field woes behind them to keep alive their play-off hopes with a crucial and nervy 27-24 victory over Clermont on Saturday.
Leaders La Rochelle, meanwhile, became the first team to book their play-off spot with a 23-13 victory at Pau.
Racing's match against Montpellier last weekend was postponed over the fall-out created by a controversial planned merger -- now abandoned -- with Parisian rivals Stade Francais.
Coming on the back of other off-field issues including a drink-driving episode involving New Zealand legend Dan Carter and the sacking of another All Black in Ali Williams after being arrested for the alleged possession of cocaine, the champions needed something to cheer on the field.
But they were left hanging on by their finger-tips late on despite Clermont's Benson Stanley having been sent off.
"This season nothing can be simple and we saw that this afternoon," said Racing coach Laurent Labit.
"We were in bad shape before the match with everything that's happened.
"We were down but the problem is not falling, the important thing is to get back up."
Victory moved Racing to just three points off the top six, and with a game in hand on sixth-placed Pau.
Bordeaux-Begles also kept their play-off hopes alive and simultaneously dented four-time European champions Toulouse's with a 22-11 victory.
Bordeaux are level on points with Racing while Toulouse, who have never before missed out on the end of season play-offs, are two points behind in ninth after a fifth defeat in six.
Racing were out of the blocks at break-neck speed with Fijian lock Leone Nakarawa crossing for a first minute try.
Stanley was sin-binned for killing the ball around the half-hour mark and another try from Kiwi Chris Masoe and 10 points from Carter's boot saw a one-sided first half end 20-0.
Clermont came out strongly after the break as Paul Jedrasiak bundled over from close range with New Zealander fly-half Stephen Brett converting.
But Clermont shot themselves in the foot when Stanley picked up a second yellow card for a dangerous tackle on Brice Dulin, and was sent off for good.
Racing capitalised immediately, creating an overlap on the left for Argentine flyer Juan Imhoff to scamper over for a third try, converted by Carter again.
- Tired and desperate -
At 27-10 and with a numerical advantage, it seemed to be game over but scrum-half Maxime Machenaud was sin-binned for killing the ball and suddenly Clermont had their tails up.
They forced a penalty try and then Fijian wing Alivereti Raka went over the whitewash, with Brett converting both to make it a three-point game.
Racing looking tired and desperate but just managed to hold on.
"When you look at the half-time score the final score is satisfying. But when you see the second half, we should be coming away with something else," said Clermont coach Franck Azema.
Australian fly-half Brock James scored 18 points as La Rochelle opened up an 11-point lead in the table.
James scored a try, two conversions and three penalties with La Rochelle's only other points coming from an Afaesetiti Amosa try.
Crucially it gave them a 26-point cushion to Bordeaux and Racing, and with only 25 points available to the Parisians and 20 to Bordeaux, La Rochelle's top six berth is assured.
"It's the first season that we've experienced something like this and we've not won anything yet," said La Rochelle centre Pierre Aguillon.
"We've in a good spell but we can't stop there."
Bayonne's return to the second division inched closer with a crushing 52-7 defeat at rampant Lyon, who ran in seven tries, including two from New Zealand Sevens international Toby Arnold.
Bayonne are 14 points from safety with a maximum 20 points available but would be cast even further adrift if Stade Francais beat Toulon on Sunday.
Grenoble kept their faint survival hopes alive with a last gasp David Mele drop goal snatching a 21-20 win over Castres.
It left Grenoble seven points behind Stade while Castres' losing bonus point moved them up a place to fifth.