Munster completed the double over the Scarlets with a 19-13 victory at Thomond Park Stadium once again reserving their best for the second half.
They led 6-3 at half time thanks to a pair of Ronan O'Gara penalties and seemed to have put the game well beyond the Welsh side when James Coughlan scored a 52nn minute try that O'Gara converted for a 16-3 lead.
The expectation was that Munster would kick on from there but Scarlets weren't in any mood to wave the white flag and a Rhys Priestland penalty and his conversion of Ken Owens 66th minute try ensured another tense finish.
In that second half Scarlets twice had players sin-binned but they still managed to cause Munster all sorts of bother with centre Jon Davies finding gaps to exploit 'n explore.
Munster were forced to work hard in defence and did so admirably up until Owen's dotted down, Scarlets given the position when a wicked bounce had the otherwise secure Denis Hurley was undone by a wicked bounce and Johne Murphy needed to make a solid tackle to avert a score.
The first half was a fairly drab affair, Davies leading the way as Scarlets ran the ball whenever the opportunity presented itself. Stephen Jones started at out-half with Priestland at full back to give the Scarlet offence greater potency.
Munster weren't shy about running the ball themselves and Simon Zebo came closest only to be denied by Dave Pearson who adjudged he's made a double movement.
O'Gara opened Munster's account when a penalty was awarded for obstruction but Jones levelled seven minutes later. O'Gara nudged them in front with his second successful strike before Jones missed a great opportunity to level just before the break.
Munster re-emerged with clear intent and O'Gara gave them an early boost with a penalty for a 9-3 lead. Then the move of the match started just outside Munster's 22 when Conor Murray left defenders dead, his break taking play into the Welsh 22 and the subsequent lineout take from Paul O'Connell leading to Coughlan's try.
Priestland and O'Gara traded penalties and then O'Gara kicked his side into a 13 point lead only to see that reduced to six when Owens scored after a Scarlets rumble.
It ended as the previous encounter, with the Scarlets trying desperately for the try that might have seen them snatch the spoils. But Munster's defence held firm and they remain very much in charge of their own destiny.
Munster: D Hurley; J Murphy, K Earls, L Mafi, S Zebo; R O'Gara, C Murray; W du Preez, D Varley, B Botha, D O'Callaghan, P O'Connell (capt), D Leamy, N Ronan, J Coughlan. Replacements: D Ryan for Leamy, T O'Leary for Murray (both 63 mins), M Horan du Preez (71), T O'Donnell for Coughlan (77). Not used: D Fogarty, S Archer, I Keatley, D Barnes.
Scarlets: R Priestland; L Williams, S Williams, J Davies, S Lamont; S Jones, G Davies; R Jones, M Rees (capt), R Thomas, L Reed, D Welch, R McCusker, J Edwards, B Morgan. Replacements: V Longi for S Jones (half-time), K Owens for Rees, G Maule for L Williams (both 63 mins), P John for R Jones, S Timani for Welch, T Knoyle for Davies (all 66 mins), K Murphy for McCosker (71 mins). Not used: D Manu. Sinbinned: Edwards (51-61 mins), K Owens (79 mins).
Referee: Dave Pearson (England).