The result puts Clermont top, at least until Sunday when Toulon meet Toulouse.
Aurelien Rougerie, Jamie Cudmore and Sitiveni Sivivatu all crossed in the first half, while Napolioni Nalaga struck late to ensure a bonus point.
Elsewhere James Hook bagged 16 points in a 31-17 victory for Perpignan on their trip to Mont-de-Marsan.
Racing Metro brushed aside Grenoble 23-3 to move up to sixth, with Juan Imhoff bagging two tries.
Bordeaux-Begles impressed with a 48-17 demolition job over Agen, leapfrogging their opponents in the process.
Rory Kockott knocked over four penalties as Castres shaded Montpellier 26-20 to continue their push towards the play-off places.