Toulouse finished Top 14 regular season at the summit of the standings thanks to victory over Montpellier on Saturday.
Clermont finished second, level on points, after running eight tries past Brive, whose relegation was confirmed.
Toulon won on the road to Lyon to book a home play-off against Racing MÃ©tro, who were edged at the death in Agen.
Castres narrowly beat Bayonne to secure the other home play-off against Montpellier.
Elsewhere, Biarritz warmed up for their Challenge Cup Final with victory over Stade FranÃ§ais while Perpignan finished with a wimper by losing to Bordeaux-BÃ¨gles.
Toulon v Racing MÃ©tro
Castres v Montpellier
Agen 25-22 Racing MÃ©tro
Biarritz 16-5 Stade FranÃ§ais
Bordeaux-BÃ¨gles 37-29 Perpignan
Castres 31-29 Bayonne
Clermont 57-14 Brive
Lyon 5-29 Toulon
Toulouse 20-13 Montpellier
Stade Toulousain 20-13 Montpellier HR
Stadium de Toulouse
Luke McAlister created two of Timoci Matanavou's three tries as Toulouse got back to winning ways.
But Montpellier hled the ball for most of the first half and went into the changing rooms at 10-10 thanks to Timoci Nagusa's try.
The game was an open affair after both teams were reduced to 14 men early on following a mass brawl.
Matanavou's third try sealed victory for Toulouse but the hosts were pushed all they continually let Montpellier back into the game with too many handling errors.
Tries: Matanavou 3
Cons: Bustos Moyano
Pens: Bustos Moyano
Yellow cards: Maestri (Toulouse 28th min); Gorgodze (Montpellier 28th min); Creevy (Montpellier 28th min)
Toulouse: 15 Clement Poitrenaud, 14 Vincent Clerc, 13 Yann David, 12 Florian Fritz, 11 Timoci Matanavou, 10 Luke McAlister, 9 Luke Burgess, 8 Louis Picamoles, 7 Thierry Dusautoir, 6 Jean Bouilhou, 5 Patricio Albacete, 4 Yoann Maestri, 3 Cencus Johnston, 2 Christopher Tolofua, 1 Jean-Baptiste Poux.
Replacements: 16 Yohan Montes, 17 Gurthro Steenkamp, 18 Romain Millo-Chluski, 19 Gregory Lamboley, 20 Jean-Marc Doussain, 21 Lionel Beauxis, 22 Yannick Jauzion. 23 Daan Human.
Montpellier: 15 Lucas Gonzalez Amorosino, 14 Timoci Nagusa, 13 Thomas Combezou, 12 Paul Bosch, 11 Martin Bustos Moyano, 10 Francois Trinh-Duc, 9 Julien Tomas, 8 Masi Matadigo, 7 Mamuka Gorgodze, 6 Fulgence Ouedraogo, 5 Aliki Fakate, 4 Mickael De Marco, 3 Giorgi Jgenti, 2 Erasmus Van Vuuren, 1 Na'ama Leleimalefaga.
Replacements: 16 Agustin Creevy, 17 Juan Figallo, 18 Drikus Hancke, 19 Alex Tulou, 20 Eric Escande, 21 Santiago Fernandez, 22 Benoit Sicart, 23 Maximiliano Bustos.
ASM Clermont Auvergne 57-14 CA Brive CorrÃ¨ze
Parc des Sports Marcel Michelin, Clermont Ferrand
No miracle then for Brive, who are sent to the ProD2.
Les CorrÃ©ziens were ahead on the hour-hour mark thanks to two early tries, but once the Clermont machine had kicked into gear, it was one-way traffic.
Sitiveni Sivivatu and Wesley Fofana both grabbed two tries each as Clermont confirmed their status has favourites for the Top 14 crown.
Tries: Sivivatu 2, Fofana 2, Faure, Russell, Murimurivalu, King
Cons: James 5, Parra 2
Tries: Figuerola, Spedding
Cons: Belie 2
Yellow card: Figuerola (Brive - 54th min)
Clermont: 15 Kini Murimurivalu, 14 Seru Nakaitaci, 13 Aurelien Rougerie, 12 Wesley Fofana, 11Sitiveni Sivivatu, 10 Brock James, 9 Morgan Parra, 8 Elvis Vermeulen, 7 Alexandre Audebert, 6 Jason White, 5 Julien Pierre, 4 Jamie Cudmore, 3 David Zirakashvili, 2 Benjamin Kayser, 1 Thomas Domingo.
Replacements: 16 Ti'i Paulo, 17 Lionel Faure, 18 Loic Jacquet, 19 Julien Bardy, 20 Ludovic Radosavljevic, 21 Regan King, 22 Brent Russell, 23 Daniel Kotze.
Brive: 15 Scott Spedding, 14 Jacques Boussuge, 13 Jamie Noon, 12 Riaan Swanepoel, 11 Ronnie Cooke, 10 Mathieu Belie, 9 Agustin Figuerola, 8 Petrus Gherardus Hauman, 7 Vincent Forgues, 6 Poutasi Luafutu, 5 Retief Uys, 4 Julien Ledevedec, 3 Pat Barnard, 2 Guillaume Ribes, 1 Pablo Henn.
Replacements: 16 Iuri Natriashvili, 17 Jefferson Poirot, 18 Olivier Caisso, 19 Simon Azoulai, 20 Thibault Dubarry, 21 Jean-Baptiste Pejoine, 22 Shane Geraghty, 23 Pablo Cardinali.
Castres Olympique 31-29 Aviron Bayonnais
Stade Pierre Antoine, Castres
Castres were pushed all the way but booked their home play-off thanks to two tries from prop Saimone Taumoepeau and another from Yannick Forestier.
Bayonne came back from 23-12 down at the break get a bonus point and finish their difficult season on a high note and Sam Gerber intercepted to score in the final minute.
Tries: Taumoepeau 2, Forestier
Cons: Teulet 2
Pens: Bernard 3, Teulet
Tries: Huget, Gerber
Cons: Potgieter 2
Pens: Boyet 5
Yellow cards: Gerber (Bayonne - 61st min)
Castres: 15 Romain Teulet, 14 Romain Martial, 13 Max Evans, 12 Romain Cabannes, 11 Marc Andreu, 10 Pierre Bernard, 9 Thierry Lacrampe, 8 Chris Masoe, 7 Yannick Caballero, 6 Ibrahim Diarra, 5 Joe Tekori, 4 Rodrigo Capo Ortega, 3 Karena Wihongi, 2 Marc-Antoine Rallier, 1 Saimone Taumoepeau.
Replacements: 16 Mathieu Bonello, 17 Yannick Forestier, 18 Matthias Rolland, 19 Steve Malonga, 20 Rory Kockott, 21 Seremaia Baikeinuku, 22 James So'oialo, 23 Luc Ducalcon.
Bayonne: 15 Yoann Huget, 14 Joe Rokocoko, 13 Thibault Lacroix, 12 Sam Gerber, 11 Marvin O'Connor, 10 Benjamin Boyet, 9 Mike Phillips, 8 Dwayne Haare, 7 Julien Puricelli, 6 Troy Flavell, 5 Mark Chisholm, 4 Abdellatif Boutaty, 3 Renaud Boyoud, 2 David Roumieu, 1 Aretz Iguiniz.
Replacements: 16 Francois Da Ros, 17 Neemia Tialata, 18 Rob Linde, 19 Francois Carillo, 20 Julien Audy, 21 Cedric Heymans, 22 Jacques-Louis Potgieter, 23 Victor Manukula.
SU Agen 25-22 Racing-MÃ©tro 92
Stade Armandie, Agen
Racing secured their play-off berth (against Toulon) despite losing a tight battle.
Agen fly-half Conrad Barnard landed fourteen point to finish as the season's top points scorer.
But it was young replacement pivot Mathieu Lamoulie who stole the limelight, winning the game for the hosts with a 79th minute penalty.
Pens: Barnard 4, Lamoulie 2
Tries: Loree 2, Imhoff
Cons: Wisniewski 2
Agen: 15 Brice Dulin, 14