Munster beat Racing Metro to secure an away tie against Harlequins in the Heineken Cup quarter-finals, while also ensuring that champions Leinster would not progress to the last eight.
The Irish province scored five tries to clinch the bonus point which edged them ahead of Leinster in the standings.
Simon Zebo claimed a hat-trick of tries, with Conor Murray and Mike Sherry also touching down for Munster.
The early dismissal of Racing flanker Antoine Battut proved a crucial moment.
Referee Wayne Barnes showed Battut a red card after just five minutes for allegedly kneeing a Munster player on the head.
Ian Keatley, playing at fly-half in the absence of the banned Ronan O'Gara, added two conversions, while Gaetan Germain kicked two penalties for the visitors.
With 12 minutes gone, Munster were penalised for engaging early at a scrum and Germain gave Racing the lead by knocking over the resulting penalty for the first points of the game.
The home side responded and scrum-half Murray darted over from five metres out for the first try in the 25th minute after Donnacha Ryan had won a lineout and Mike Sherry set up the score.
Keatley landed the conversion to secure the additional two points.
Three minutes later Zebo crossed the line after prop Dave Kilcoyne made a break, Munster won the ruck ball and Keatley and Earls helped set up the Irish winger, who dived over.
Keatley pulled his conversion to the left but the Irish province now had all the momentum.
Germain reduced the deficit to six points however when the full-back kicked his second penalty following an offside infringement.
Five minutes before the interval Mike Sherry was the man with the ball as the Munster pack crashed over the line for try number three, Keatley again missing the conversion.
The crucial fourth try arrived on 48 minutes courtesy of a fine individual effort by Zebo, who collected his own kick down the wing, before touching down. Keatley was successful with his conversion on this occasion.
Zebo further emphasised his side's superiority by finishing off a fine move among the home backline by planting the ball down in the corner to complete his hat-trick of tries.
Keatley hit the post with his conversion attempt from the left touchline.
Racing's Masi Matadigo and Munster's Patrick Butler were sin-binned late in the game while Jacques Cronje was adjudged to have grounded the ball just short of the line in the final minute after consultation with the Television Match Official.
A relieved Munster finish second in Pool 1 and retain their hopes of a third Heineken Cup success at the expense of their Irish interprovincial rivals, who have won Europe's premier club competition for the last two years.
Munster: F Jones; D Howlett capt, K Earls, J Downey, S Zebo; Ian Keatley, C Murray; D Kilcoyne, M Sherry, BJ Botha; D O'Callaghan, D Ryan; P O'Mahony, T O'Donnell, J Coughlan.
Replacements: D Varley, W du Preez, J Ryan, B Holland, P Butler, D Williams, JJ Hanrahan, C Laulala.
Racing Metro 92: G Germain, J Jane, G Bousses, A Dumoulin, S Bobo, O Barkley, M Belie, J Brugnaut, B Noirot, B Sa, K Ghezal, F Metz, A Batut, B Le Roux, J Cronje,
Replacements: T Bianchin, A Lo Cicero, JP Orlandi, J Qovu Nailiko, B Fall, S Dellape, S Descons, M Matadigo,
Referee: Wayne Barnes (Eng)