Tim Ryan went over late following two earlier Jeremy Manning penalties as a second-string visiting side went down fighting at the Arms Park.
But coach Declan Kidney knows his team must find a cutting edge if their hopes of reclaiming the Celtic crown are not to be dashed before the autumn.
This was a huge test of character for the European champions with the absence of so many front-line players through imposed rest periods and injuries. Munster returned to the city of their finest hour following last May’s Heineken Cup final triumph in the Millennium Stadium without 12 of the players who started that game. Shaun Payne, Ian Dowling and John Kelly, making his 138th appearance, were the only survivors, with Trevor Halstead, Denis Fogarty and Eugene McGovern out through injury.
To their immense credit, Munster’s youngsters and club players defended stoutly and frustrated a Blues side that, in direct contrast to Munster, fielded 12 internationals and dominated both possession and territory.
Munster trailed just 9-3 at the break and when Manning slotted over a second penalty there was a glimmer of hope of an unlikely win for the visitors.
But it was to prove the closest Munster would get to their hosts who finally found their finishing their touch with two tries in five minutes. Marc Stcherbina danced through to open space for Chris Czekaj to cross before Scott Morgan, a summer signing from Leeds Tykes, galloped over following a break by the pack.
Ryan paid for his team-mates’ earlier misdemeanours when he was shown the yellow card for a professional foul just moments after taking the field as a replacement.
Worse was soon to follow as 22-year-old lock Donncha Ryan, also making his first start, followed to the sin bin after being caught offside to leave Munster down to 13 men for a three-minute spell. Robinson’s penalty also left them 22-6 down.
Ryan returned as Munster finished by far the stronger, shrugging off Lion Martyn Williams before sliding over for a consolation try. However, they need their backs to be scoring if they are to get anything from the next few weeks without their stars.
CARDIFF: R Williams; C Czekaj, J Robinson, M Stcherbina (T Shanklin, 65), M Luveitasau (N Macleod, 71); N Robinson, M Phillips; G Jenkins (J Yapp, 68), R Thomas (G Williams, 2-7), T Filise; D Jones (B Davies, 62), R Sidoli; S Morgan, X Rush (capt), M Williams (R Sowden-Taylor, 73).
MUNSTER: C Cullen; S Payne, J Kelly (capt), J Downey (M Lawlor, 71), I Dowling; J Manning, T O’Leary; D Hurley, F Sheahan, F Pucciariello (T Ryan, 55); D Ryan, C Wyatt; R Noonan (B Cuttriss, 52), J Coughlan, J O’Sullivan (F Pucciariello, 55-65).
Referee: Rob Dickson (Scotland).
Leinster U20 58 Munster U20 8
By Barry Coughlan
LEINSTER made a smashing start to the U20 Interprovincial Championship at Donnybrook last night when they romped home against Munster.
Apart from the early stages, this was never a real contest and Leinster were full value for their huge victory.
Indeed, Munster had to wait until the closing stages to score their only try, after Leinster had run in for eight, having established a 22-3 half-time lead.
Owen Fleck had two tries, with one each from Killian Byrne, Kevin Sheehan, Tom Walsh, Robbie Copeland, Jamie Hagan and Paul O’Donoghue.
Ian Keatley kicked six conversions and two penalties.
Jeff Power kicked an early penalty for Munster who had to wait until late for a consolation try from Edwin Torrie.
Magners League: Glasgow 23 Dragons 24.