This may have completed their best start to a Heineken Cup campaign since 2007, but a quick glance in the Munster dressing-room afterwards would have fooled the neutral.
The slumped shoulders and sombre mood betrayed a proud side still ill at ease with themselves, as they conspired with the countdown clock to repel a dangerous late Scarlets surge.
The final palpitations were so unnecessary. The game seemed to have turned so decisively in the third quarter, in the manner of the age-old Cup tradition that backbones this arena.
Trailing 9-3 in an error-strewn affair, the visitors were loitering in this contest with bristling intent and, as Rhys Priestland lined up a penalty, the momentum seemed to be shifting irrevocably to the Welsh outfit, particularly after the aforementioned had supplanted the injured pivot Stephen Jones at half-time.
However, the enigmatic playmaker skewed his shot horribly wide, from whence Conor Murray sped dizzily from defensive mode into attack, culminating in Munster's only meaningful backline sortie all day.
Some fine handling from the returning Keith Earls, Niall Ronan and Denis Hurley allowed Johne Murphy to steam up his right wing into the Scarlets' danger zone.
Jonathan Edwards was binned at the subsequent ruck, after which a Munster catch and drive propelled James Coughlan over for the sole Munster try.
Ronan O'Gara's conversion for 16-6 seemed to seal the encounter, if not his penalty in the 63rd minute.
Or at least it would have done in this Munster side's pomp. At 19-6, they built multiple phases in Scarlets territory and one sensed that they would go in for the kill. Yet a killer instinct is sorely lacking in this side, hence the surfeit of tight finishes in this group.
"That's a ruthlessness that you need at this level and that's what we need to take advantage of," bemoaned coach Tony McGahan.
A worrying lack of mental edge and a poor physical effort in terms of soak tackling allowed the visitors to surge into contention, responding with a 66th-minute Ken Owens try that capitalised on a Hurley boob and some soft fringe tackling.
Scarlets' inexperience denied them the chance to turn the knife but a better side would have exacted the fullest retribution for Munster's sloppy final quarter. It was, dare one say it, the ugliest of wins. But still a win for all the brooding introspection.
"We work so hard for our points and then we let the opposition straight back in with three points or field position," said McGahan. "If we have any thoughts of going further in this competition, we need to make sure we recognise that."
The opening quarter offered up a bleary-eyed blizzard of errors from both sides, with Munster struggling to impose their physicality and lacking clear structure, while Scarlets lived on the edge of the gainline, more often than not fluffing their lines.
The contrast in styles was evident from early on; Scarlets sent Jon Davies down the 10 channel in an attempt to puncture holes in the home rearguard and they created decent numbers in wide areas.
Munster, living on the edge at the breakdown, were able to repel much of what the visitors slung at them, although Scarlets undid much of their enterprise with a series of crass handling errors and forward passes.
The home side were seeking to impose themselves up front and some vigorous counter-rucking and a fine Paul O'Connell line-out steal ensured that Scarlets' visits to the '22' would be mercifully brief.
Further up the field, O'Connell dominated the carrying stakes. But a couple of lost line-outs and Dave Pearson's version of scrum lottery, in which 19-year-old loosehead Rhodri Jones put in an outstanding effort, stifled momentum.
Sadly, the maul was ignored and only occasionally did Munster seem comfortable when rumbling in the danger areas; with that, Keith Earls and Simon Zebo barely saw the ball for long stretches, Hurley seemed uncertain running back while Lifeimi Mafi's contributions were comical rather than clinical. A couple of missed tackles from Coughlan emphasised the sense of frustration among the home supporters who were conscious that Munster's three-match winning run had not automatically reinstated the two-time champions' erstwhile swagger.
"There were 26 minutes before we had any sustained pressure over two phases and 26 minutes at home is a long time to get yourself in the game," observed McGahan.
"A lot of that was down to the way Scarlets played, but more importantly I think it was our inaccuracy that did that. The players are disappointed with the performance, we really came here today to improve what we have been trying to do and while we got through, we recognise there is a hell of a lot of work to do."
At the end of that first half at least, Munster did manage to show what they were capable of: a series of fine sorties creating the space and width for Earls to combine with Zebo -- the pair's dash and footwork would have sealed a try but for fine defensive cover and the young wing's double movement.
A 6-3 lead was reward for Munster persistence and a reflection that Scarlets had not managed to eke out any significant profit margin from all that early endeavour when their slick movement had exploited some weak tackling.
Which is much like how the day ended, too.
Munster's hunger to win remains, if not their intimidating aura of yore, with O'Connell's tour de force and Murray's excellence spearheading the effort.
"The players are really quiet in there, they are really disappointed with their performance," conceded McGahan.
"But you need to step back and give yourself a pat on the back. We are in a pool that is so competitive and you need to sit back sometimes and say well done and say we are going in the right direction."
Munster -- D Hurley; J Murphy, K Earls, L Mafi, S Zebo; R O'Gara, C Murray (T O'Leary 63); W du Preez (M Horan 71), D Varley, B Botha, D O'Callaghan, P O'Connell (capt), D Leamy (D Ryan 63), N Ronan, J Coughlan (T O'Donnell 77).
Scarlets -- R Priestland; L Williams (G Maule 63), S Williams, J Davies, S Lamont; S Jones (V Iongi h-t), G Davies (T Knoyle 66); R Jones (P John 66), M Rees (capt, K Owens 63), R Thomas, L Reed, D Welch (S Timani 66), R McCusker, J Edwards (K Murphy71), B Morgan.
Ref -- D Pearson (England).