Toulouse will have to wait until the last game of the French rugby season to make sure of a Top 14 play-off spot while Perpignan slipped closer to a first relegation since 1911.
Nineteen-time champions Toulouse, who have reached the semi-finals at least for the past 20 seasons, were held to a 19-19 draw by relegation-threatened Oyonnax to occupy the sixth and last place for the play-offs.
They are level on points with Stade Francais who claimed a bonus point in a 37-23 win over and Bordeaux-Begles.
But Stade have the toughest task of the last weekend in two weeks' time when they must travel to table-topping Toulon while Toulouse are at home to mid-table Grenoble.
Oyonnax are second bottom on 50 points, the same as Bayonne, who drew 21-21 at Grenoble, and Perpignan who were humbled 46-31 by European champions and league leaders Toulon in Barcelona.
While victory helped Toulon -- for whom French first-five Frederic Michalak scored 26 points -- go top of the table, defeat left seven-time champions Perpignan third from bottom.
Perpignan's hopes of avoiding joining fellow ailing rugby giants Biarritz in the second tier next season look slim as their final match is a trip to Clermont, where the hosts are unbeaten in 76 matches.
Third-placed Clermont lost 22-6 at Racing Metro who became the fourth side to make sure of a play-off spot.