Bristol bottom of Pool 2 after loss at La Rochelle
La Rochelle: (14) 35
Tries: Nowell, Latu, Botia, Seuteni, Berjon Cons: West 5
Bristol Bears: (7) 7
Try: Bates Con: Worsley
La Rochelle condemned Bristol Bears to a second successive Investec Champions Cup defeat with a comfortable bonus-point victory at Stade Marcel-Deflandre.
Former England winger Jack Nowell produced an acrobatic finish out wide to give the hosts the lead before Tolu Latu powered over from close range to stretch their advantage.
Bristol hit back before the interval with a fine solo try by Jack Bates but replacement Lavani Botia shoved over to restore La Rochelle's cushion after the break.
The Premiership side remained committed and Harry Randall was hauled down just short of the line following Gabriel Oghre's clever intercept but La Rochelle ended their resolve and claimed the bonus through UJ Seuteni.
With the clock in the red and Bristol all out of steam, the hosts opted for a scrum on the five-metre line to exert more dominance instead of ending the game.
As Randall tried to stop number eight Gregory Alldritt at the base, replacement scrum-half Thomas Berjon picked up the loose ball and sniped over to add further gloss to the scoreline.
Bristol, who were beaten in their opening game by Leinster, have failed to claim a point in this season's competition and drop to the bottom of Pool 2.
Victory for two-time winners La Rochelle follows their opening win over Bath as they move level on points with Leinster at the top of the table.
La Rochelle overpower Premiership high-fliers
Bristol have thrilled in the Premiership this season with their fluid style of play but they have ultimately fallen short against two of European rugby's biggest names.
Four-time winners Leinster turned on the style with a flurry of second-half tries in their opening game at Ashton Gate and La Rochelle ground them down in France.
It began with a stunning try from familiar foe Nowell, who has tormented Bristol in the past with former club Exeter. The wing remained in play to gather Ihaia West's crossfield kick and elegantly ground the ball while he was in mid-air.
Bristol nearly responded as Kalaveti Ravouvou stepped past Nowell and passed to Benjamin Elizalde but the full-back was dragged into touch by opposite number Dillyn Leyds.
Man-of-the-match Latu was deemed to have the ball down at the bottom of a crowded melee to increase La Rochelle's lead but Bristol fired back with a crossfield kick of their own as Elizalde made amends for failing to score the visitors opening try.
The full-back clipped the ball wide as Bates beat Leyds in the air before brushing off another defender and stepping past the last to hand Bristol a lifeline.
La Rochelle's greater strength in depth was demonstrated by the introduction of Botia from the bench and the Fijian all-but sealed victory with his try from close range.
Seuteni's powerful finish sealed number four and Berjon crossed for the fifth, leaving Bristol needing victory at home against Benetton on 12 January to kickstart a European campaign in danger of ending in the pool stages.
Line-ups
La Rochelle: Leyds; Nowell, Seuteni, Danty, Thomas; West, Kerr-Barlow; Wardi, Latu, Atonio, Douglas, Skelton, Jegou, Haddad, Alldritt (capt).
Replacements: Lespiaucq, Penverne, Colombe-Reazel, Dillane, Botia, Cancoriet, Berjon, Favre.
Bristol: Elizalde, Bates, Ravouvou, Janse van Rensburg, Ibitoye; Worsley, Randall Genge, Oghre, Chawatama, Luatua (capt), Owen, Grondona, Heenan, Mata.
Replacements: Thacker, Woolmore, Lahiff, Hodgson, Grondona, Marmion, Lane, Jenkins.
Referee: Chris Busby (Ireland)