Scarlets won for the first time in eight visits to Musgrave Park as they outmuscled Munster 13-6 in horrendous playing conditions.
The visitors earned themselves a first ever win at the ground, and at the same time, ended Munster's proud unbeaten record there since May 2008.
The home side saw six changes to the side which had last played, while Scarlets also made some changes from their win at Edinburgh two weeks ago.
Munster had all of the early pressure, with Scarlets camped in their own 22 for the majority of the opening period of the game.
Scarlets had the first chance to open the scoring though, with Aled Thomas missing his penalty kick on 18 minutes, as the ball was spooned wide, the wind playing its part in keeping the game scoreless.
Ian Keatley opened the scoring for Munster on 23 minutes, kicking from the 22 line, to give the home side something for all of their early pressure. Thomas then made up for his earlier miss on 29 minutes, with an easier kick at goal, bringing the visitors level.
Play was held up for some time with just five minutes of the first half to play, as Munster's Niall Ronan received attention on the pitch before being stretchered off the field. The flanker had been cleared out of a ruck pretty convincingly by Jake Ball.
Munster spent the final two minutes of the half working the ball through several phases close to the Scarlets line, and with one final push, were unable to convince the TMO that they had taken the ball over the whitewash.
A 3-3 half-time scoreline was scant reward for Munster's early pressure, but was well earned by Scarlets' robust defence.
Despite kicking with the wind, Thomas missed a penalty goal attempt just three minutes in to the second half, after Munster had collapsed a scrum on their 22 metre line.
Scoring opportunities were few and far between, and Thomas tried using the wind to drop kick on 55 minutes, but that attempt was also wide of the mark.
Munster lit up the game on the hour, as Felix Jones charged forward, offloading to Keatley, who chose to chip and chase, leading to a scramble for the ball, but the home side couldn't make anything of the resultant penalty scrum.
Thomas kicked Scarlets into the lead on 68 minutes, with a kind bounce off the post helping the ball over the line. With ten minutes left to play, Andy Fenby chased down a long kick, and as fullback Jones fumbled the ball, it was the Scarlets winger who took advantage of the wet conditions, to take the game out of Munster's reach.
Thomas converted to give his side a ten point lead.
Thomas missed two more penalty attempts, hitting the post on both occasions, while JJ Hanrahan closed the scoring with a last minute consolation penalty for Munster.
Pens: Keatley, Hanrahan
Pens: Thomas 2
Munster: 15 Felix Jones, 14 Doug Howlett (c), 13 Casey Laulala, 12 James Downey, 11 Luke O'Dea, 10 Ian Keatley, 9 Duncan Williams, 8 Paddy Butler, 7 Niall Ronan, 6 Dave O'Callaghan, 5 Billy Holland, 4 Ian Nagle, 3 Stephen Archer, 2 Mike Sherry, 1 Wian Du Preez.
Replacements 16 Damian Varley 17 Marcus Horan, 18 BJ Botha, 19 Dave Foley, 20 CJ Stander, 21 Peter Stringer, 22 JJ Hanrahan, 23 Denis Hurley.
Scarlets: 15 Morgan Stoddart 14 Nick Reynolds, 13 Gareth Maule, 12 Gareth Owen, 11 Andy Fenby, 10 Aled Thomas, 9 Gareth Davies, 8 Craig Price, 7 Johnathan Edwards (c), 6 George Earle, 5 Richard Kelly, 4 Jake Ball, 3 Jacobie Adriaanse, 2 Emyr Phillips, 1 Phil John.
Replacements 16 Kirby Myhill, 17 Shaun Hopkins, 18 Samson Lee, 19 Johan Snyman, 20 Dan Thomas, 21 Rhodri Williams, 22 Dan Newton, 23 Adam Warren.
Referee: Laurent Cardona