Munster turned in a sloppy display at Rodney Parade where a magical match-winning try from Rio Dyer drove the Dragons to a deserved 23-17 win.
Graham Rowntree’s men seemed to be getting on top just before half-time, with a two-try spurt – Stephen Archer and Ben Healy scored within three minutes of each other – giving them a 17-15 lead.
However, a rather listless second half saw neither team take control and poor Munster defence allowed winger Dyer to tear through for a decisive 71st-minute try.
Former Munster back JJ Hanrahan slotted over his sixth penalty goal of the day, right at the death, as the Dragons celebrated their first victory over Munster since December 2015.
Back-to-back defeats in Wales leave Munster in 15th place in the BKT United Rugby Championship table, ahead of next Saturday’s visit of Zebre Parma to Musgrave Park.
Reflecting on his side’s lacklustre performance, head coach Rowntree said afterwards: “I told the lads I’m not happy with our discipline, inaccuracy, the way we were forcing things and our error count.
“I can’t have this. I can’t dress it up any better than that. I was surprised about our inaccuracy particularly going into their 22, and our ability to keep the ball in that key area. That really shocked me, I’ll be honest with you.
“Whoever you play you are going to have a challenge, particularly when you play away from home regardless of what’s happened in the Dragons camp this week. I expected better in terms of the stuff we can do better.
“It was just so poor. We had eight turnovers in the first half and were ill-disciplined. We lost lineouts, knocked on and we never got a foothold in the game.”
Dragons centre Jack Dixon was penalised for not releasing as Munster got off to a spritely start. The central second-minute kick, just outside the 22, was sent over by out-half Healy for 3-0.
Angus O’Brien, the eventual URC player-of-the-match, impressed under the high ball on two occasions before Hanrahan, who moved to Newport from Clermont Auvergne in the summer, got his new side on the board.
The Kerry native nailed his first penalty from outside the visitors’ 10-metre line, but Munster responded with strong carrying off a lineout as both Dan Goggin and Jack O’Sullivan made good ground through the middle.
However, the Dragons’ well-drilled defence soon forced the province back to the halfway line and Munster suffered a double injury blow when Keith Earls, with a suspected hamstring injury, and Jean Kleyn (HIA) both had to go off.
In their absence, Hanrahan took centre stage as he fired over four penalties between the 15th and 34th minutes. Number 8 O’Sullivan was slow to roll away firstly, allowing the home side to take the lead for the first time.
Munster’s error count increased with a miscued lineout and a Mike Haley knock-on, and then Hanrahan punished a high tackle from Archer to make it 9-3 early in the second quarter.
Archer fell on the wrong side of a ruck for the concession of three more points, and the Dragons continued to hound Munster into mistakes and costly turnovers.
A turnover penalty won by Malakai Fekitoa saw the men in red hold firm, but former Ulster hooker Bradley Roberts’ brilliant charge downfield led to a fifth successful penalty from Hanrahan.
Crucially for Munster, they owned the final five minutes of the opening half. Healy’s well-placed restart was won back by Haley and the Tipperary youngster soon made a sharp break to send Simon Zebo into space on the left.
The experienced winger was brought down by a high tackle from Dyer. Craig Casey took the penalty quickly and four phases later, prop Archer crashed over for his try, with referee Sam Grove-White also sin-binning Dyer for the earlier high challenge.
Munster capitalised on Dyer’s absence, quickly profiting from an obstruction call against the Dragons. Casey attacked the blindside from an advancing maul and his well-timed pass put Healy over past Rhodri Williams’ diving tackle.
The Munster number 10 knocked over the 40-metre conversion for good measure, putting two points between the sides as Rowntree’s charges headed back to their dressing room with some hard-earned momentum.
The Dragons blew an opportunity to respond early on the restart when opting for a scrum instead of a certain three points. Good work at the breakdown from Peter O’Mahony allowed Munster to move back out of their 22.
Dyer intercepted a pass from Goggin just as Munster were beginning to get on the front foot, while a couple of forward passes from Goggin and replacement Tadhg Beirne saw them cough up possession again.
Prop Aki Seiuli won the breakdown battle to keep Munster out of try-scoring range. The third quarter finished scoreless as the Welsh outfit, in head coach Dai Flanagan’s first home game in charge, turned down another kickable penalty.
Their lineout did not go to plan on this occasion and Munster soon forced a scrum penalty, lifting the tempo through replacements Paddy Patterson and debutant Edwin Edogbo, the first Cobh Pirates player to line out for Munster in the professional era.
With 11 minutes remaining, Hanrahan had his chance but was surprisingly off target with a 40-metre penalty attempt, but that miss mattered little in the end.
Dyer managed to power away on a 55-metre run, breaking initially between Fekitoa and O’Mahony before evading Haley’s tackle, for a superb individual try.
The Dragons fans roared with delight as the final whistle neared. Their team’s cause was helped by Jack O’Donoghue’s yellow card for side-entry. Hanrahan fired over from the tee with the last kick of the match.