There will be a new Top 14 champion after Castres missed out on a top-six finish with a final-day defeat to Toulon.
Neither Bordeaux Begles nor Stade Francais can make the play-offs in the Top 14 after suffering painful defeats in the penultimate round.
Grenoble look to be heading for a relegation play-off after losing at home to their nearest rivals Agen.
Toulon centre Mathieu Bastareaud explained why he is headed for New York after the Rugby World Cup.
Greig Laidlaw's boot and a pair of tries from Apisai Naqalevu helped Clermont Auvergne battle back to beat Stade Francais on the road.
La Rochelle put Pau to the sword and Castres also enhanced their chances of reaching the play-offs with a win in Bordeaux.
Toulon may have been at a numerical disadvantage for most of the second half but they still managed to defeat Top 14 leaders Toulouse.
Paul O'Connell has been linked with Toulon, but the outgoing Stade Francais forwards coach says he will not join another club next season.
Tries from Carl Fearns, Mickael Ivaldi and Thibaut Regard helped Lyon get back to winning ways in Saturday's Top 14 action.
There were big wins for 2017-18 Top 14 finalists Castres and Montpellier on Saturday, with Benjamin Urdapilleta inspiring.