Toulon and Clermont face tricky ties this weekend as the Top 14's dominant duo look to conserve energy ahead of next weekend's European Cup semi-finals.
Clermont face the tougher task as they host reigning champions Toulouse at the Marcel Michelin stadium ahead of a crunch clash with Munster in Montpellier.
But Toulon will not be relishing either a trip to Grenoble, who until recently had been unbeaten at home this season.
With both their weekend rivals out of European competition and battling for a strong finish to the regular season, the top two face a tough challenge.
Not least because they will have one eye on next weekend's endeavours with Toulon travelling to London to tackle in-form Saracens in their semi-final.
Toulouse look a safe bet to finish third in the regular season but need another win to make sure.
And Clermont's France international hooker Benjamin Kayser knows they cannot afford to take the champions lightly.
"We're preparing to play a Toulouse team looking to make a statement ahead of the play-offs," he said.
"I believe they want to come and claim a scalp and maybe their position as outsiders and the fact most people are talking about us and Toulon (for the title) suits them.
"Although obviously the European Cup semi-final is on our minds, but when you play Toulouse you can't afford to look ahead to the next challenge the next week."
Should Clermont win they would equal Stade Francais's record of 59 straight victories at home.
A week later they host lowly Bordeaux-Begles.
Two victories might give them the chance of overtaking leaders Toulon, if the red and blacks slip up, but Kayser says that's not on their minds.
"Honestly that's not part of our thinking at all," he said. "It's not that we don't care but whether you finish first or second you'll still have a very tough semi-final."
Given the gaps between the various teams there seems little realistic chance of Toulouse breaking into the top two, even in the event of a victory on Sunday.
They look fairly sure for third place and only a remarkable collapse by either Castres, Racing Metro or Montpellier could give Perpignan a chance of sneaking into a top six play-off spot.
For that to happen the Catalans would need to win away to relegated Agen on Saturday and then again at Montpellier two weeks later.
Their best chance of a team slipping up is probably Montpellier, who face a tough trip to the Basque Country to tackle Bayonne.
If they lost that, there could be a grandstand clash at the Yves-du-Manoir stadium in two weeks.
Stade Francais host Racing Metro in the Paris derby at the Stade de France on Sunday.
Racing are pushing hard for a top four finish and a home quarter-final. They desperately need a win so they can face Castres at home on the final weekend with a winner-takes-all clash for that fourth spot.
Stade, meanwhile, may be tempted to rest some star names ahead of their Challenge Cup semi-final against Perpignan.
With ninth placed Stade well out of the running to qualify for the European Cup next season through the league, their only chance to do so is by winning Europe's secondary competition.