Munster gave coach Alan Gaffney a winning send-off with victory in the Celtic Cup final at Lansdowne Road.
CELTIC CUP FINAL
Munster (20) 27
Tries: A Horgan, R O'Gara, M Mullins
Cons: R O'Gara (3)
Scarlets (10) 16
Tries: M Phillips
Cons: C Thomas
Pens: C Thomas (3)
The Irishmen took a 20-10 lead into the break thanks to converted tries from Anthony Horgan and Ronan O'Gara, who also kicked a penalty and a drop-goal.
The Scarlets kept in touch with a Mike Phillips converted try and two penalties from fly-half Ceiron Thomas.
Two more Thomas penalties brought the Scarlets to within four points, but a late Mike Mullins try settled matters.
The alarm bells started ringing quickly for the Scarlets as Munster made easy in-roads into opposition territory with their first attack.
And the weak tackling was again evident as winger Horgan burst past two defenders far too easily to touchdown in the left corner after five minutes.
O'Gara, playing for the first time since March after a knee injury, used the helping wind to good effect to curl the conversion through the posts.
A Ceiron Thomas penalty got the Scarlets on the board, but they were soon on the back foot again as Munster stepped up the pressure.
They edged towards the Scarlets line with wave after wave of midfield breaks, before O'Gara drifted past the scrambling defence after flanker David Wallace had been held up inches short.
Scarlets cut the deficit down to just four points through Phillips' converted try, but O'Gara used all his experience to take Munster clear again in first-half injury time.
Phillips forced his way over after retrieving possession after Aisea Havili was held up on the line - although television replays suggested the winger had managed to ground the ball.
Thomas added a fine conversion, but O'Gara's penalty and injury-time drop goal gave Munster a healthy 20-10 lead at the break - but not before desperate defence had driven Phillips back over the tryline seconds before the whistle.
Lock Donnacha O'Callaghan should have given Munster a perfect start to the second-half, but he lost the ball as he stretched out towards the line.
Thomas added his second penalty to bring the Scarlets back to within four points as the game entered the final half hour.
O'Gara then missed a relatively easy penalty and the momentum seemed to be swinging the Scarlets' way.
They failed to take advantage, though, and Mullins' converted try three minutes from time gave Munster some breathing space at the death and sent Gaffney back to his native Australia a proud man.
Munster: S Payne; P Devlin, M Mullins, R Henderson, A Horgan; R O'Gara, P Stringer; M Horan, F Sheahan, J Hayes, D O'Callaghan, P O'Connell, A Quinlan, D Wallace, A Foley (capt).
Replacements: D Leamy for P Devlin (62), G McIlwham for M Horan (23).
Not Used: J Flannery, T Hogan, M Prendergast, P Burke, J Storey.
Scarlets: B Davies; G Evans, M Watkins, T Selley, A Havili; C Thomas, M Phillips; P John, M Rees, J Davies, V Cooper, C Wyatt, S Easterby (capt), G Thomas, A Powell.
Replacements: S Finau for A Havili (55), A Gravelle for M Rees (69), A Jones for C Wyatt (63), G Quinnell for A Powell (55).
Not Used: D Maddocks, C McDonald, G Bowen.
Referee: Joel Jutge (France)