Toulouse overturned a 14-point deficit to beat Castres 34-27 in a seven-try Top 14 thriller on Saturday.
The defending champions came from behind twice to snatch victory with former All Black Luke McAlister in the thick of the action.
Clermont won away to Agen to stay in touch with Toulouse at the top of the standings while Biarritz did their hopes of survival the world of good with victory over Brive.
Bayonne, however, are in deep trouble after losing to Montpellier.
In the capital, Stade FranÃ§ais claimed a bonus-point win over bottom club Lyon to boost their play-off chances while Perpigan and Toulon played to a thrilling 22-22 draw.
Racing MÃ©tro 22-13 Bordeaux-BÃ¨gles
Toulouse 34-27 Castres
Agen 20-29 Clermont
Biarritz 26-11 Brive
Montpellier 37-26 Bayonne
Stade FranÃ§ais 40-19 Lyon
Perpignan 22-22 Toulon
Stade Toulousain 34-27 Castres Olympique
Stade Ernest Wallon, Toulouse
Toulouse treated the Ernest Wallon crowd to a grandstand finished as they came back from 10 points down in the last quarter to claim a deserved win.
Castres hadn't scored a try since January but were first to cross the whitewash when Karena Wihongi profited from the carnage after Romain Teulet hit the post from a penalty to crash over.
Castres went 14-0 up when Romain Martial intercepted inside his own half and raced home.
Toulouse came back just before the break as Luke McAlister landed a penalty and Yves Donguy went over in the corner after Chris Masoe was sent to the sin bin.
The hosts went ahead for the first time early in the second half when prop Cencus Johnston powered over but Castres moved back in front when Yannick Caballero broke of the side of a scrum to score from 10m out.
Pierre Bernard added two penalties and the champions looked in a spot of bother. But Florian Fritz charged over from an excellent run, flattening two defenders on his way.
The home side sealed a remarkable win in the dying minutes when McAlister kicked cross-field and replacement prop Gillian Galan crashed over.
Tries: Donguy, Johnston, Fritz, Galan
Cons: McAlister 4
Pens: McAlister 2
Tries: Wihongi, Martial, Caballero
Cons: Teulet 3
Pens: Bernard 2
Yellow cards: Masoe (Castres - 38th min - repeated offside)
Toulouse: 15 Yannick Jauzion, 14 Timoci Matanavou, 13 Florian Fritz, 12 Yann David, 11 Yves Donguy, 10 Luke McAlister, 9 Luke Burgess, 8 Shaun Sowerby, 7 Yannick Nyanga, 6 Jean Bouilhou, 5 Patricio Albacete, 4 Romain Millo-Chluski, 3 Cencus Johnston, 2 Jaba Bregvadze, 1 Daan Human.
Replacements: 16 Jeremie Falip, 17 Gurthro Steenkamp, 18 Gregory Lamboley, 19 Sylvain Nicolas, 20 Jean-Marc Doussain, 21 Maxime Payen, 22 Gillian Galan, 23 Johnson Falefa.
Castres: 15 Romain Teulet, 14 Romain Martial, 13 James So'oialo, 12 Romain Cabannes, 11 Marc Andreu, 10 Pierre Bernard, 9 Thierry Lacrampe, 8 Chris Masoe, 7 Yannick Caballero, 6 Ibrahim Diarra, 5 Rodrigo Capo Ortega, 4 Matthias Rolland, 3 Karena Wihongi, 2 Marc-Antoine Rallier, 1 Yannick Forestier.
Replacements: 16 Mathieu Bonello, 17 Anton Peikrishvili, 18 Benjamin Desroches, 19 Jannie Bornman, 20 Rory Kockott, 21 Seremaia Baikeinuku, 22 Pierre-Gilles Lakafia, 23 Michael Coetzee.
SU Agen 20-29 ASM Clermont Auvergne
Stade Armandie, Agen
Clermont make it nine games without defeat and keep the pressure on Toulouse in the process while Agen slip off the pace in the play-offs race.
Agen took the early lead when Conrad Barnard chipped ahead for Junior Pelesasa, who needed the TMO to validated his score. But Brock James kicked Clermont into a 12-11 lead at half time after Opeti Fonua was given a yellow card for a dangerous tackle on Anthony Floch.
South African wing Brent Russell extended the visitors' lead in the second half before the Clermont pack secured victory with some impressive driving to put Benjamin Kayser over.
Try: Pelesasa 5
Tries: Russell, Kayser
Cons: Jame, Skrela
Pens: James 5
Yellow card: Fonua (Agen - 29th min)
Agen:15 Silvere Tian, 14 Saimoni Vaka, 13 Miguel Avramovic, 12 Junior Pelesasa, 11 Romain Edmond Samuel, 10 Conrad Barnard, 9 Maxime Machenaud, 8 Opeti Fonua, 7 Ueleni Fono, 6 Jean Monribot, 5 Adri Badenhorst, 4 Dewald Senekal, 3 Gert Muller, 2 Jalil Narjissi, 1 Arsene Nnomo.
Replacements: 16 Julien Janaudy, 17 Semisi Telefoni, 18 Lisiate Fa'aoso, 19 Marc Giraud, 20 Alexis Bales, 21 Manu Ahotaeiloa, 22 Belisario Agulla, 23 Beka Sheklashvili.
Clermont: 15 Anthony Floch, 14 Brent Russell, 13 Seru Nakaitaci, 12 Regan King, 11 Jean-Marcel Buttin, 10 Brock James, 9 Ludovic Radosavljevic, 8 Elvis Vermeulen, 7 Alexandre Audebert, 6 Jason White, 5 Nathan Hines, 4 Loic Jacquet, 3 Daniel Kotze, 2 Benjamin Kayser, 1 Raphael Chaume.
Replacements: 16 Benoit Cabello, 17 Lionel Faure, 18 Julien Pierre, 19 Alexandre Lapandry, 20 Kevin Senio, 21 David Skrela, 22 Gavin Williams, 23 Adrien Oleon.
Biarritz Olympique 26-11 CA Brive CorrÃ¨ze
Parc des Sports d'Aguilera, Biarritz
Biarritz claimed consecutive victories for only the second time this season to put some breathing room between themselves and the relegation zone.
Despite losing a number of balls at line-out time and failing to showing the positive intentions they did a week ago, Biarritz led 9-6 at the break thanks to the boot of - yes, you guessed it - Dimitri Yachvili.
The second half was a different story however as BO upped the tempo and were soon rewarded as Julien Peyrelongue set up a try for Dane Haylett-Petty.
The home pack plied the pressure to win a penalty try at scrum time in the 65th minute.
The Basques controlled the closing stages and a late try from Scott Spedding was not enough for Brive, who now lead Biarritz by just three points in the standings.
Tries: Haylett-Petty, Penalty try
Cons: Yachvili 2
Pens: Yachvili 4
Pens: Caminati 2
Yellow cards: Guyot (Biarritz); Boussuge; Khinchagashvili (Brive)
Biarritz: 15 Iain Balshaw, 14 Taku Ngwenya, 13 Marcelo Bosch, 12 Damien Traille, 11 Dane Haylett-Petty, 10 Julien Peyrelongue, 9 Dimitri Yachvili, 8 Talalelei Gray, 7 Benoit Guyot, 6 Wenceslas Lauret, 5 Manuel Carizza, 4 Jerome Thion, 3 Francisco Gomez Kodela, 2 Arnaud Heguy, 1 Sylvain Marconnet .
Replacements: 16 Benoit August, 17 Yvan Watremez ,18 Pelu Taele-Pavihi, 19 Raphael Lakafia, 20 Jean Pascal Barraque, 21 Benoit Baby, 22 Ilikena Bolakoro, 23 Eugene van