Northampton's long-time benefactor and former chairman, Keith Barwell, has had better birthdays than the one he spent watching his beloved Saints put through the Heineken Cup mincer in Milton Keynes. The leggy Munster wing Simon Zebo galloped to a second-half hat-trick to secure the top-seeded quarter-final place and a home tie with Ulster – and a potential semi-final in Ireland, against Edinburgh or Toulouse – for the team beaten by Barwell's club in the final of 2000 but who, in more recent years, have been part of a perennial Irish push into the latter stages.
Munster's success stalled last season when they missed the quarter-finals for the first time in 13 years and Leinster were champions. By roaring back with six pool wins, Munster have righted that wrong, albeit with late, late dropped goals by the evergreen Ronan O'Gara in the first two matches, against Northampton and Castres last autumn.
This return fixture at Saints' borrowed home was watched by a record Stadium mk crowd and turned on Munster's ferocious and skillful operation in the post-tackle area. Their buckling scrummage conceded two penalty tries – Paul O'Connell, the grizzled Munster captain, could not remember that happening to a team he was in – but they trumped everything else a Northampton side lacking the dropped England wing Chris Ashton could throw at them. From 19-19 at half-time and a 34-29 lead with 15 minutes remaining, Munster finished with five tries and 24 points from the boot of O'Gara, the competition's all-time record scorer.
Ashton, who was said by Saints' coach, Jim Mallinder, to have returned to training on Thursday and Friday after a reported row, is leaving for Saracens in the summer. It is rumoured James Downey will follow the Ulster-bound Roger Wilson back to Ireland while the Gloucester and England No 8 Luke Narraway fancies Franklin's Gardens.
Dylan Hartley, like Ashton and six other Saints, will join up with England tomorrow. Ashton will have played just twice in two months by the time of the Scotland match on Saturday week and may fear the form of Charlie Sharples and Dave Strettle is better than his. Hartley, the Northampton captain who recently extended his contract to 2015, said: "It's Chris's decision to move, I'll still be his mate. The reason I signed is I don't think there's anywhere else you'd want to be as a young English rugby player. We were there or thereabouts in this competition" – an invaluable win in Munster on weekend one was as close as a last-second swing of O'Gara's boot – "but losing at home to Scarlets certainly cost us."
Whereas O'Gara will turn 35 before the April quarter-finals, Zebo is a 21-year-old in the side due to the former All Black wing Doug Howlett's achilles tendon injury. The lad from Cork wowed the 3,000 Munster supporters with two classic finishes – on the touchline from Denis Hurley's sweet pop out of a tackle and with a slashing inside break – either side of an interception sprint from halfway. "The offloads from [Lifeimi] Mafi and Hurley, and the playmaking of Rog [O'Gara] makes it easy," Zebo said. "Dougie [Howlett] is like a mentor to me. He's been good to look up to."
It was not Munster's highest away score in the Heineken – though surely sweeter than the 55 points they put on Viadana in 2002-03 – but, surprisingly, it completed their first clean sweep of pool wins, better than in their Cup-winning seasons 2006 and 2008.
"I probably would have been confident about getting out of the group but not about winning six out of six," O'Connell said. "We've got a long way to go to get up to the standard of the Leinsters and the Toulouses but I just think the attitude was right."
As for Northampton, finalists against Leinster last season and England's sole quarter-finalists the year before, they suffered the ignominy common to Leicester, Bath, London Irish and Gloucester of finishing third in their pool, unable even to drop into the Amlin Challenge Cup.
Scorers: Northampton Saints: Tries Penalty try 2, Armstrong; Conversions Lamb 2, Myler; Penalties Lamb 4; Drop goal Lamb.
Munster: Tries Botha, Murphy, Zebo 3; Conversions O'Gara 3, Keatley; Penalties O'Gara 6.
Northampton: B Foden; J Elliott (S Armstrong, 69), G Pisi, J Downey, V Artemyev; R Lamb (S Myler, 73) L Dickson (M Roberts, 73); S Tonga'uiha (A Waller, 66), D Hartley (capt), B Mujati (P Doran-Jones, 65), S Manoa, M Sorenson (C Day, 62), C Clark (B Nutley, 62), P Dowson, R Wilson.
Munster: D Hurley; J Murphy, K Earls, L Mafi (D Barnes, 77), S Zebo; R O'Gara (I Keatley, 74), C Murray; W du Preez (M Horan, 55), D Varley (D Fogarty, 74), BJ Botha (S Archer, 73), Donncha O'Callaghan (M O'Driscoll, 73), P O'Connell (capt), D Ryan, P O'Mahony (Dave O'Callaghan, 73), J Coughlan.
Referee R Poite (France).