Paris - Fijian flanker Levani Botia led La Rochelle to a stunning display of off-loading brilliance that crushed defending Top 14 champions Clermont 51-20 on Saturday.
Winger Gabriel Lacroix scored a hat-trick as the hosts, basking in sunshine in front of a raucous sell-out Stade Marcel-Deflandre -- where they were unbeaten last year, ran in six tries in a scintillating first half against a Clermont side which had two players yellow carded.
The high-octane game was effectively decided at 43-6 at half-time, with last season's regular-season table-toppers in flying form.
As slick as La Rochelle looked, with English flyhalf Ryan Lamb pulling the strings, Clermont produced an error-ridden, flat-footed display with new Scotland scrumhalf Greg Laidlaw struggling to implement anything close to a gameplan.
La Rochelle bounced back from their disappointing defeat by Stade Francais last week by opening the scoring after just 42 seconds, Lacroix crossing in a hint of what was to come.
Camille Lopez responded with two penalties for Clermont, but after that it was one-way traffic, All Black No 8 Victor Vito and Botia completing outclassing their opposition backrow.
Veteran Fiji lock Jone Qovu was instrumental in opening the floodgates, slipping English winger David Strettle's tackle and off-loading to Alexis Bales who found Lacroix on his outside to scamper home for his second.
An attacking line-out soon after saw a well-drilled pack peel off and crash over for La Rochelle's third try, the ubiqitous Vito credited with the touchdown.
Clermont prop Raphael Chaume was yellow carded in the 31st minute, swiftly followed into the sin bin by winger Remy Grosso after deliberately knocking down a try-scoring pass.
Referee Romain Poite was left with no other option than to also award a penalty try.
With Clermont two men down, La Rochelle turned the screw, backs and forwards linking wonderfully for Kiwi hooker Hikairo Forbes to go in under the posts for an improbable fifth try.
Scrumhalf Bales jinked over from close range through Rougerie's half-attempt at a tackle for a sixth, leaving Clermont trailing 43-6 at half-time after Lamb banged over his fifth conversion.
The second period got off to a horrendous start for Clermont, Lacroix crossing for his hat-trick after Lopez spilled the kick-off and the ball was worked right, where the impressive Paul Jordaan's inch-perfect grubber was picked up with aplomb by the winger.
La Rochelle continued to make inroads thanks to the rampaging Qovu and Botia, listed as flanker but often popping up in midfield and proving a real nuisance to Clermont's backline.
The visitors' fightback had to come and Samoan No 8 Fritz Lee chose a good line to eventually cross for Clermont's first try in the 56th minute.
Australian replacement centre Peter Betham bagged a second for Clermont after a break by Grosso.
La Rochelle, however, made sure to go over the 50-point barrier when Jean-Victor Goillot kicked a straightforward penalty for a fantastic victory that will leave Clermont's defensive coaches scratching their heads if they are to stand any chance of defending their title.