Scarlets claimed the scalp of PRO12 leaders Munster with a stunning 30-21 comeback win at Thomond Park.
The Welsh region won at the Limerick ground for only the second time - they were 19-12 winners back in September 2003 - to give a big boost to their play-off hopes.
Despite a sloppy start, converted tries from Jaco Taute, Darren Sweetnam and Conor Oliver gave Munster a commanding 21-6 half-time lead, with Dan Jones booting two penalties for the Welshmen in reply.
However, Scarlets really got their running game going in the third quarter, pouncing for three quick-fire tries from Hadleigh Parkes, Johnny McNicholl and Tom Williams as the hosts' poor kicking and defending was ruthlessly punished.
Jones kicked a penalty and added all three conversions and although they finished strongly, Rassie Erasmus' men could not avoid their first defeat in nine PRO12 matches.
The hosts gave away a cheap three points in the second minute, Taute's knock-on leading to Jones splitting the posts, and further handling errors blighted the province's early attacks.
A high-quality 12th-minute try got Munster on the right road, Tyler Bleyendaal's inviting offload and Dave O'Callaghan's cleverly-angled run seeing the big flanker hauled down just short before Francis Saili's long pass set up Taute for the left corner.
Bleyendaal's curling conversion was answered by Jones' second successful penalty, but Munster were clinical again entering the second quarter, pressing from a maul and then a string of passes freed up Sweetnam for a seven-pointer out wide.
Former Leinster lock Tadhg Beirne, who was Scarlets' man-of-the-match against Zebre, was crucial in thwarting another Munster maul, however a Dan Goggin break saw the province surge back into the 22 and number eight Oliver took advantage of a gap to run in his second senior try.
Playing with the wind on the restart, Wayne Pivac's side made gradual inroads with fly-half Jones converting the second of two penalty attempts. But they soon burst into life, with Aled Davies making a timely impact off the bench.
A blistering six-minute spell that yielded three tries started with centre Parkes touching down from Davies' well-placed kick over the top. Fellow New Zealander McNicholl then showed his pace on a brilliant 40-metre run-in and with Bleyendaal shooting up out of the line, Jones' long pass put winger Williams over in the right corner.
The Scarlets number 10 added a cracking conversion to Williams' 61st-minute score, suddenly putting Munster nine points in arrears.
Staring at their first Thomond Park loss of the season, the hosts improved late on but Scarlets' sturdy defence held firm despite Saili and Dave Kilcoyne both going close to tries.