A late try from wing Julien Malzieu helped Clermont snatch a 30-23 over Perpignan at Stade AimÃ©-Giral on Friday.
Clermont provisionally took over at the top of the table with an entertaining victory, just their second away from home this season.
Fiji centre Noa Nakaitaci, scrum-half Thierry Lacrampe and left-wing Malzieu scored tries for les Juanards while the hosts earnt a losing bonus thanks to a penalty try and a score from winger Sofiane Guitoune.
Wales international fly-half James Hook kicked two conversions and three penalties for the Catalans, who were off to a confident start when Hook knocked over two early place-kicks but Perpignan then gifted the visitors a try.
Algeria-born Guitoune, who made his France debut earlier this month against Tonga, came in off his right wing into the backline but without looking sent a wayward pass that eluded two team-mates.
Nakaitaci pounced on the loose ball and ran in under the posts, with Kiwi fly-half Mike Delany kicking the extras for a 7-6 lead.
Perpignan responded well and broke from right to left with Hook sending South African wing Wandile Mjekevu over in the corner.
Referee Sebastien Minery originally referred the score to the TMO but having then consulted his touch judge, controversially changed his mind and decided Hook's pass had been forward, a decision that television replays demonstrated to be questionable.
The Catalans didn't lose heart, though, and piled on the pressure in the forwards.
That told as Clermont's Scottish lock Nathan Hines and prop Clement Ric were both shown yellow cards, after which Perpignan were handed a penalty try as the visitors' scrum disintegrated when being shoved back over their line.
Delany and Hook exchanged penalties and Perpignan went in at the break leading 16-10.
Clermont came out all guns blazing after the restart and although prop Thomas Domingo had what looked like a valid score overruled by an unsighted video referee, Lacrampe took advantage of a moment's hesitation in the home defence to dart out from behind a ruck and touch down under the posts, Delany again converting.
Perpignan looked set to go back in front as Mjekevu kicked ahead down the left and appeared to have won the foot-race to the loose ball, only for Clermont captain Aurelien Rougerie to slide in and kick the ball out of his hands a yard from the tryline.
Perpignan weren't to be denied, though, and Guitoune exchanged passes with Mjekevu before beating Malzieu on the outside and charging into three Clermont defenders, with his momentum taking him over the line to score.
Hook kicked the conversion and Perpignan led 23-17.
Delany was replaced by Australian Brock James who immediately kicked a penalty.
He then made a decisive break in midfield before passing to Malzieu to dot down on the left, with James converting too.
Tries: Penalty try, Guitoune
Pens: Hook 3
Tries: Nakaitaci, Lacrampe, Malzieu
Cons: Delany 2, James
Pens: Delany, James 2
Yellow cards: Hines, Ric
USA Perpignan: 15 James Hook, 14 Sofiane Guitoune, 13 Tommaso Benvenuti, 12 David Marty, 11 Wandile Mjekevu, 10 Camille Lopez, 9 Dewaldt Duvenage, 8 Luke Narraway, 7 Alasdair Strokosch, 6 Justin Purll, 5 Romain Taofifenua, 4 Luke Charteris, 3 Giorge Jgenti, 2 Romain Terrain, 1 Sebastien Taofifenua,
Replacements: 16 Maxime Delonca, 17 Kisi Pulu, 18 Sebastien Vahaamahina, 19 Karl Chateau, 20 Tom Ecochard, 21 Watisoni Votu, 22 Joffrey Michel, 23 Paulica Ion.
ASM Clermont Auvergne: 15 Lee Byrne, 14 Naipolioni Nalaga, 13 Aurelien Rougerie, 12 Noa Nakaitaci, 11 Julien Malzieu, 10 Michael Delany, 9 Thierry Lacrampe, 8 Fritz Lee, 7 Julien Bardy, 6 Gerhard Vosloo, 5 Nathan Hines, 4 Loic Jacquet, 3 Clement Ric, 2 Benoit Cabello, 1 Thomas Domingo.
Replacements: 16 Ti'i Paulo, 17 Raphael Chaume, 18 Jamie Cudmore, 19 Damien Chouly, 20 Ludovic Radosavljevic, 21 Brock James, 22 Jean Marcellin Buttin, 23 Vincent Debaty.
Venue: Stade AimÃ© Giral, Perpignan
Referee: SÃ©bastien Minery