Bristol were outshone by Clermont in their first Champions Cup game since 2008, as the French side put on a thrilling seven-try attacking display.
The Bears - Challenge Cup winners in October - struggled in the step up to Europe's premier competition as Clermont's Japanese full-back Kotaro Matsushima claimed a hat-trick.
Wales back Ioan Lloyd's score earned Bristol a four-try bonus point.
But a star-studded Clermont backline was too much for the Bears to handle.
Clermont light up empty Ashton Gate
Both sides observed a moment of silence before kick-off to pay tribute to 16-year-old Luke Wheaton, a former member of Bristol's junior academy who died in last week's explosion at a waste water treatment works near the city.
Once play began, in a far cry from the slower, defensive style of the Autumn Nations Cup, three-time Champions Cup finalists Clermont showed off their attacking flair.
An impressive one-handed offload from France international Alivereti Raka sent Matsushima over in the third minute, before centre Apisai Naqalevu intercepted Wales fly-half Callum Sheedy's pass to score.
The visitors' back three combined with devastating effect again as Damian Penaud went over in the corner.
Bristol eventually found a way into the game, capitalising on a 5m scrum as number eight Nathan Hughes sent the ball right and newly capped England international Max Malins danced his way through defenders to score.
But with Bristol fly-half Sheedy down injured, Naqalevu threw a basketball pass over the head of scrum-half Harry Randall for Matsushima to score the bonus-point try.
Sheedy was soon back on his feet and Bristol managed to reduce the deficit before half-time as hooker Bryan Byrne scored in a maul.
The Bears looked to be mounting a comeback as Henry Purdy barrelled down the left wing and, as he was heading into touch, sent a smart offload for Randall to score.
But Clermont soon extinguished the Bears' spark with a second try for Penaud before number eight Fritz Lee added his name to the scoresheet.
Rugby league convert Ratu Naulago came on for his first Bristol appearance and still Clermont did not let up as Matsushima completed his hat-trick.
The hosts at least ended with a flourish as Malins' quick penalty saw Lloyd go over in the corner, before Charles Piutau gathered the full-back's kick to score under the posts.
Bristol face Connacht in Galway next Sunday, while Clermont play Irish side Munster at home on Saturday.
There are two pools of 12 teams in the complex new-look tournament format. Each team plays two other sides from their pool in home and away fixtures.
After that, the top four teams from each pool will go on to contest the quarter-finals and the sides placed fifth to eighth in each pool will drop into the European Challenge Cup.
Line-ups
Bristol: Malins; Leiua, O'Conor, Piutau (capt), Purdy; Sheedy, Randall; Woolmore, Byrne, Afoa, Holmes, Joyce, Earl, Thomas, Hughes.
Replacements: Capon, Thomas, Sinckler, Attwood, Heenan, Uren, Lloyd, Naulago.
Clermont: Matsushima; Penaud, Naqalevu, Moala, Raka; Lopez (capt), Parra; Falgoux, Pelissie, Slimani, Timani, Jedrasiak, Cancoriet, Vahaamahina, Lee.
Replacements: Fourcade, Ravai, Falatea, Lanen, Veredamu, Bezy, Tiberghien, Vili.