The home side opened with a try from Benjamin Geledan in the 20th minute, and never looked back, scoring 31 unaswered points before Munster had a late consolation try from Sean Scanlon converted by Scott Deasy.
Stade Rochelais led 10-0 at the break, when Rob Penney as planned rang the changes, keeping just two of his backline Doug Howlett and Luke O'Dea in what was nine changes overall. Stade also made changes but without much disruption to their rhythm and they extended their lead in the 52nd minute with a length of the field move that ended with a try for replacement Francois Herry.
Another replacement, Uini Antonio, scored their fourth try and although Christy Condon did marvellously well to deny a certain score, it proved to be just a delay as the French scored from the subsequent scrum.
Scanlon's 70th minute try was converted by it's creator Scott Deasy to end the scoring.
Munster: D Hurley; D Howlett, D Barnes, J Downey, L O'Dea; I Keatley, D Williams; D Kilcoyne, G Slattery, S Archer; B Holland, B Hayes; T O'Donnell, S Dougall, J Coughlan.
Replacements: D Casey, M Horan, J Ryan, W du Preez, C Condon, P Donnellan, C O'Flaherty, P Butler, B O'Mahony, P Stringer, J Holland, S Deasy, JJ Hanrahan, C Laulala, S Scanlon, R O'Mahony.