Joris Segonds booted 26 points to help Stade Francais to a 46-27 victory over Lyon on Friday, a fifth consecutive Top 14 win that sees them temporarily leapfrog Toulon into sixth place in the table.
The result leaves Stade in the last play-off place on 66 points, with just one more weekend of the regular season to play. It also guaranteed Bordeaux-Begles a spot in the play-offs, while ensuring Lyon would not qualify.
Toulon, who host Bordeaux-Begles, and Castres, away to Brive, are both on 60 points and could re-take Stade's play-off place on Saturday.
Stade scored four tries through Fijian winger Sefanaia Naivalu (2), Tongan full-back Telusa Veainu and South African scrum-half James Hall, with Segonds kicking all four conversions and a further six penalties.
Lyon also crossed the whitewash four times, through Baptiste Couilloud, Dylan Cretin, and New Zealanders Toby Arnold and Charles Ngatai, but it was not enough against the resurgent Parisian club.
Clermont, currently in fifth place on 67 points, are away at league leaders Toulouse in Saturday's late game, while fourth-placed Racing (68pts) play at Agen.
It is a big weekend at the bottom of the table as well. With Agen already relegated, it appears to be between second-bottom Pau (41pts) and Bayonne (44pts) to face the second division play-off winners in another play-off to see who will feature in next season's Top 14.
Pau have the daunting task of travelling to European Cup finalists La Rochelle, who are one point behind leaders Toulouse and eager to book a home semi-final, while Bayonne are also on the road at European Challenge Cup winners Montpellier (50pts).