Montpellier march on, Brive climb off the bottom
Top 14 leaders Montpellier sit six points clear at the summit after an emphatic display against Castres, Les Cistes winning 45-7.
A dominant opening 40 minutes - aided by Maama Vaipulu's trip to the sin bin - saw Montpellier pile on 21 points.
Nicolaas Janse van Rensburg and Bismarck du Plessis both crossed, while Ruan Pienaar kicked eight points and Francois Steyn converted a drop goal.
There was no let up after the break as Montpellier added another three tries, while all Castres could muster was Armand Batlle's converted score.
Toulouse are hot on Montpellier's heels thanks to a 37-33 victory over Stade Francais, the accuracy of Zack Holmes and Jean-Marc Doussain proving crucial as both sides scored four tries.
Wandile Mjekevu and Cheslin Kolbe plus 10 points from Holmes gave Toulouse a seven-point advantage at half-time, and although Stade Francais fought back the visitors were able to cling on.
The four points moves them into second place above Racing 92 - who face Lyon on Sunday.
La Rochelle made it back-to-back wins to cement their top-six place as Bordeaux-Begles were brushed aside 31-20, the hosts running in five tries.
They are joined in the European places by Pau after a 33-12 triumph over Oyonnax - who slip to the bottom of the table.
Oyonnax drop to 14th place after Brive claimed a first league win of 2018 by beating Agen 15-12.
Gaetan Germain was Brive's hero with five penalties, while Agen could only register four in a tactical battle that also saw three yellow cards.