In another weekend of upsets Biarritz's season went from bad to catastrophic on Saturday as the went down to second from bottom Dax while lowly Brive beat Stade Français on Friday.
Brive's status as a Top 14 team is all but assured after they ground out an uninspiring 11-3 win over Stade Francais on Friday.
Clermont host Perpignan in the pick of the Top 14's Round 22 clashes. The championship leaders host the in-form Catalans who are still under pressure from Castres.
As anticipated, Frédéric Michalak will return to former club Toulouse when his contract with the Sharks expires.
Beaten in Montpellier on Sunday, Toulouse are concentrating on their upcoming Heineken Cup final rather than the Top 14 according to assistant coach Philippe Rougé-Thomas.
France and Sharks fly-half Frédéric Michalak is set to return home as Toulouse have confrimed that he will meet club president René Bouscatel in the coming days.
Toulouse crashed to another Top 14 defeat at Montpellier on Sunday, going down 17-15 after a desperate first 50 minutes saw them 17-3 adrift.
Montauban were the big winners of Round 21 as they ended Perpignan's eight-game winning streak.
Clermont assured their place in the Top 14 semi-finals with hard fought 16-11 over Biarritz at Stade Aguiléra on Friday.
Dax loose forward Thomas Lièvremont has been named as the French club's coach starting next season. Lièvremont follows in the footsteps of older brother Marc, who gave up his role at Dax to take charge of the French national team.
Sale Sharks and England flanker Magnus Lund is set to join French Top 14 side Biarritz at the end of the current season.
Clermont travel to Biarritz on Friday in the game of the weekend as both teams try to make amends for defeats last week.
Toulouse brought Castres back down to earth with a bump as the giants of French rugby dominated their hosts to easily win 16-6 at Pierre-Antoine on Wednesday.
Patrice Lagisquet's future as coach of Biarritz is in serious doubt after admitting a decade at the Basque club has starting to take its toll.
Perpignan, Castres and Dax were the big winners in a weekend of characterised by a bunch of close results and one annihilation.