Clermont failed to close the gap on La Rochelle as Montpellier recorded an impressive 28-19 bonus point win on Sunday.
First-half tries from wingers Joe Tomane and Timoci Nagusa as well as hooker Bismarck du Plessis put Montpellier in the drivers seat with a 17-6 lead at the break.
Morgan Parra narrowed the deficit for Clermont with an early penalty in the second half before David Strettle restored hope with a try in the 54th minute to make it a one point contest.
But Clermont couldn't kick on as Montpellier scored through Benjamin Fall, while a late Frans Steyn drop-goal denied Clermont a losing bonus point.
Pau solidified their spot in the top four after a testing 18-12 win in a try-less match against Castres 18-12 at Stade du Hameau.
Former All Black Tom Taylor scored all the points for Pau with six penalties from the tee, while Castres goal-kicker Benjamin Urdapilleta managed four penalties.
The result sees Toulon drop to sixth in the standings.
League leaders La Rochelle continue to set the pace in France as they thumped last year's champions Racing 92 38-15 away from home.
After an early Dan Carter penalty, La Rochelle asserted their dominance early with tries from Victor Vito and Jone Qovu, and a Brock James penalty, pushing the visitors out to a 15-3 lead.
Racing hit back through Gerbrandt Grobler before Elliot Roudil crossed for La Rochelle's third try to see the visitors enter the second half up 22-8.
Two penalties from James extended the lead to 20 points before Leone Nakarawa closed the gap with a 63rd minute try, but Roudil's second of the evening and a Jean Victor Goillot penalty put the result beyond doubt.
La Rochelle now lead Clermont by eight points.
Toulon romped to a 12-try, 82-14 victory over Bayonne with Liam Gill, Bryan Habana, Juan Smith and Axel Muler grabbing a brace each.
The first-half demolition started seven minutes in, with Gill touching down, and there was no let up. Habana (twice), Smith and Axel Muller all crossed before Mathieu Bastareaud brushed swatted away two tacklers to touch down on half-time.
Gabiriele Lovobalavu's try sandwiched in between them was just a blip in the Toulon attacking prowess.
The second-half was a non event, mainly how much Toulon could rack up on their counterparts, with Smith, Gill, Juan Martin Fernandez Lobbe, Levan Chilachava and Muller crossing for further scores.
Brive had the boot of Gaetan Germain to thank in their victory over Toulouse, with the 26 year-old Frenchman kicking seven penalties in their 21-19 win.
In a first-half overshadowed by indiscipline, Brive's Patrick-Albert Toetu and Toulouse fly-half Toby Flood saw yellow. Flood and Germain had kicked two penalties to level the game up 13 minutes in.
Having seen Germain kick them ahead with a penalty 20 minutes in,the yellow to Flood shortly after seemed to galvanise them, with Jean-Marc Doussain adding two penalties before Flood's return.
With Toulouse back to fifteen, Bonneval's try and Flood's conversion put them in a commanding position at 19-9, before Germain narrowed the margin to seven at the break.
But three Germain penalties in the opening 11 minutes of the second half put Brive into a narrow lead they would not surrender.
Lyon recorded a 35-33 victory over Stade Francais in a game which saw Taiasina Tuifua and Pascal Pape sent off for throwing punches in the final minutes.
A Sekou Macalou try in the opening minute gave Stade an early lead before Frederic Michalak converted a penalty for Lyon. Stade saw Hugh Pyle yellow carded for playing the ball on the ground, while continued infringements led to a penalty try being awarded to Lyon.
Michalak converted but Stade bounced back before half-time as Jules Plisson converted a penalty and then converted Waisea Nayacalevu's try for a 17-10 half-time lead.
Plisson added a penalty after the restart before a penalty try looked to bring Lyon back into the game. Macalou was sin-binned for his part in the decision, but within three minutes, Waisea Nayacalevu had crashed over for his second try for Stade.
Plisson kicked two penalties to give them a 33-17 lead, but what followed was a complete capitulation in the final quarter.
A Carl Fearns try, two Lionel Beauxis penalties and a Delon Armitage try gave Lyon a deserved victory before the two late red cards.
Bordeaux Begles scored six tries in a convincing 46-14 victory over Grenoble.
Three tries in either half saw Bordeaux clinch the win with Romain Lonca, Louis-Benoit Madaule and Sebastien Taofifenua touching down before half-time, with three Gilles Bosch penalties the best Grenoble could manage.
Simon Hickey added two penalties and converted Cyril Cazeaux's second-half try before Ole Avei and Metuisela Talebula added two further tries. Aly Muldowney grabbed Grenoble's only try which sees them 13 points behind Stade Francais in 12th.