Munster fell to defeat in their final Investec Champions Cup pool game as Northampton Saints came with a strong finish in the final quarter to claim victory at Thomond Park.
Munster did secure their passage into the Round of 16 due to the losing bonus point picked up.
Munster led 15-7 at the break after Northampton were reduced to 13 players with a red card to hooker Curtis Langdon just before the interval and a yellow card to full-back George Furbank three minutes earlier.
Northampton hit the front at the end of the opening quarter when scrum-half Alex Mitchell crossed and his half-back partner Fin Smith converted.
Jack Crowley reduced the margin nine minutes from the break with a penalty from 30 metres and Munster hit the front two minutes from the break when Antoine Frisch finished after a tapped penalty.
Crowley converted and then in stoppage time at the end of the opening half Peter O’Mahony scored in the right corner to lead 15-7 at the break.
Smith pulled back a penalty three minutes after the restart with the wind behind him before Munster got in for their third try when Gavin Coombes scored several phases after another tapped penalty.
That pushed Munster 20-10 in front after 49 minutes but Northampton hit back and Smith landed a penalty and a drop goal to cut the gap to four points.
Crowley pushed the lead out to 23-16 after 64 minutes but another penalty from Smith left four between them.
Northampton went back in front when Sam Graham scored and Smith converted nine minutes from time and Munster were unable to produce a late winner but are through to the last 16 in the Investec Champions Cup.
Champions Cup Round 4 Round-Up
Munster secured passage into the Champions Cup knockout stages for the 22nd time after securing a losing bonus-point against the Northampton Saints.
Tom Ahern and Simon Zebo departed with injuries.
Munster: Simon Zebo (Sean O’Brien 43); Calvin Nash, Antoine Frisch, Alex Nankivell (Joey Carbery 76), Shane Daly; Jack Crowley, Craig Casey; Jeremy Loughman (Josh Wycherley 67), Niall Scannell (Eoghan Clarke 67), Oli Jager (John Ryan 50); Tom Ahern (Brian Gleeson 40), Tadhg Beirne (c); Peter O’Mahony (Alex Kendellen 65), John Hodnett, Gavin Coombes.