Clermont took the provisional lead of the Top 14 on Friday thanks to hard-fought 22-17 win over champions Perpignan at Stade Marcel Michelin.
The teams were level at 6-6 at the break after Nicolas Laharrague nailed his second drop-goal just before the hooter in reply to a drop from Anthony Floch and a Brock James penalty.
Clermont threw everything into their attack in the first 40 minutes but were unable to find a crack in the dogged Catalan defence.
The Top 14 champions were not overextending themselves on attack in the first half, rather looking to play percentage rugby.
In the second half however Stade Marcel Michelin saw the protagonists lay into each other at a level of intensity rarely seen.
The visitors drew first blood when hooker Marius Tincu finished off a fantastic line break by loose forward Ovidiu Tonita to put the Catalans up by five.
But the clash's first try only raised Clermont's game even higher as les Jaunards turned on the class. James reduced the gap and then put his side ahead with two penalties as the locals plied the pressure.
Under the relentless pressure Perpignan lost Damien Chouly to a yellow card for cynically killing the ball before Floch scored what a magnificent try for Clermont off the back of some tireless work from their pack.
James and David Mélé exchanged penalties as the visitors mounted a late rally, but the evening belonged to Clermont who took a small piece of revenge for two consecutive defeats to Perpignan, including last year's final,
Pens: James 3
Drops: Floch, James
Pens: N.Laharrague, Mélé
Drops: N.Laharrague 2
Yellow cards: Chouly (50')Schuster (17') (Perpignan) ; Scelzo (17'), Bonnaire (69)(Clermont)
Clermont: 15 Anthony Floch, 14 Napolioni Nalaga, 13 Gavin Williams, 12 Gonzalo Canale, 11 Julien Malzieu, 10 Brock James, 9 Kevin Senio , 8 Elvis Vermeulen, 7 Julien Bonnaire, 5 Thibaut Privat (cap), 4 Jamie Cudmore, 6 Alexandre Lapandry, 3 Martin Scelzo, 2 Mario Ledesma, 1 Vincent Debaty.
Replacements: 16 Cabello, 17 Thomas Domingo, 18 Alexandre Audebert, 19 Julien Pierre, 20 Morgan Parra, 21 Lavea, 22 Wesley Fofana 23Davit Zirakashvili.
Perpignan: 15 Phillip Burger, 14 Adrien Planté, 13 David Marty, 12 Jean-Philippe Grandclaude, 11 Jeoffrey Michel, 10 Nicolas Laharrague, 9 David Mélé, 8 Ovidiu Tonita, 7 Grégory Le Corvec, 6 Damien Chouly, 5 Guillaume Vilaceca, 4 Olivier Olibeau, 3 Nicolas Mas (cap), 2 Jérome Schuster, 1 Marius Tincu.
Replacements:16 Guillem Guirado, 17 Kisi Pulu, 18 Robins Tchale Watchou, 19 Sebastien Chobet, 20 Adrien Planté, 21 Maxime Mermoz, 22 Farid Sid.