After that, they performed as if they believed the job was already done and dusted, they visibly took their foot off the accelerator, Scarlets saw their chance and took it in highly impressive fashion.
Three converted tries in the space of five minutes changed everything.
Suddenly, Scarlets were 30-21 in front and clearly had Munster badly rattled. The brilliance that had gone before was replaced by bumbling mistakes and a whole host of poor judgment calls. They might have been displeased at the way they were refereed by Welshman Dan Jones but in the end they had themselves to blame as they suffered only their second defeat in 17 matches.
It was all so much in contrast to what had gone before. Munster’s lead try after 12 minutes was an absolute cracker and the ideal riposte to an opening minute penalty for Scarlets by out-half Daniel Jones.
Ronan O’Mahony got the move going with an incisive infield break and found Dave O’Callaghan at his elbow.
The big number six shook off a couple of tackles before surging up to the Scarlets posts where quick possession saw Conor Oliver find Francis Saili with a precise skip pass and the centre went over unopposed, Bleyendaal adding the points with a fine kick.
Another Jones penalty intervened before Munster’s second try came on 21 minutes when a pass by Jaco Taute to Darren Sweetnam was deemed to be flat rather than marginally forward by the TMO, the winger juggling before getting the touchdown, Bleyendaal again converting from a wide angle.
Scarlets head coach Wayne Vipac had cast aspersions on Munster’s style of play during the week but he was made to question the wisdom of his words once again on the half hour when the home side engineered yet another outstanding try.
It came as the result of a magnificent high catch of a high kick by Sweetnam who sent Dan Goggin away on a dynamic midfield break after which he linked with Saili who sent the ever alert Oliver over. Once again Bleyendaal added the points.
Ironically, though, Vipac was to have the last laugh. Munster created further scoring opportunities before half time but Scarlets held out and then proceeded to dominate the opening 20 minutes of the second-half.
Three fine tries by skipper Hadleigh Parkes, full-back Johnny McNicholl and wing Tom Williams midway through, all converted by Jones, turned the game on its head, leaving the Scarlets 30-21 ahead and with Munster very much at sixes and sevens. A crowd returned at 16,472 that perhaps understandably believed the result was a formality was now shaken to its core.
There was to be no way back. Dave Kilcoyne was held up inches short and denied a try that would have been worth a couple of bonus points but in the end they took nothing from a game that looked in the bag for so long and it was Scarlets who were celebrating a famous victory.
J Taute; D Sweetnam, F Saili, D Goggin, R O’Mahony; T Bleyendaal capt, D Williams; D Kilcoyne, R Marshall, S Archer, D Foley, B Holland, D O’Callaghan, T O’Donnell, C Oliver.
A Conway for Taute 54; K O’Byrne for Marshall 62; B Scott for Archer 65; D O’Shea for Foley 66;
J McNicholl; DTH van der Merwe, S Hughes, H Parkes capt, T. Williams; D Jones, J Evans; W Jones, R Elias, W Kruger, T Price, T Beirne, A Shingler, J Davies, W Boyde.
I Nicholas for McNicholl 46; A Davies for J Evans 46; A Thomas for D Jones 70; M Allen for Boyde 72; R Bernardo for Price 74; N Thomas for Kruger 75; L Garrett for W Jones 76;
Dan Jones (Wales).