Munster were made to pay for a sluggish start – they were 17-3 in arrears at half-time – as the Newport Gwent Dragons claimed the scalp of the Magners League leaders at a wintry Rodney Parade.
There were no excuses offered by Tony McGahan, the head coach of high flyers Munster, after they suffered a 14-point defeat at the hands of an energetic and well-organised Dragons side.
"Firstly, I'd have to give credit to them (the Dragons) for their work at the breakdown which I thought was excellent," he said.
"They kicked very well, used their possession and took their chances. Hats off to them, we can't have any quibble or offer any excuses."
A first half stranglehold took the Newport Gwent Dragons, who were ranked second-from-bottom before kick-off, into a lead that they never gave up as Munster failed to impose themselves on the match played in snowy conditions.
The result took the Dragons up to eighth in the table, leapfrogging Connacht, Glasgow Warriors and Benetton Treviso, while Munster's lead at the top has been cut to four points after Ulster won in Italy.
The home side were in control by half-time and could easily have been much further ahead than their 17-3 lead. Disappointingly for the visiting fans, Munster hardly threatened during the period and shot themselves in the foot by having two players yellow carded as well.
Home out-half Jason Tovey missed a couple of long range penalties early on and decided to play the territorial game on the slippery surface.
Those missed kicks saw the Dragons unrewarded for their efforts in the first 20 minutes but that soon changed when number 8 Toby Faletau, who was released from Wales squad duties, drove his way upfield and presented the ball at a ruck.
The ball went across the backs for Tovey to give centre Tom Riley a lovely pass on a direct run through the Munster midfield for a neat try.
Munster hardly got out of their own half, and soon lost centre Sam Tuitupou for a high tackle on Tovey.
The Dragons took advantage as former Wales flanker Gavin Thomas was just held up by a brilliant last-gasp tackle from scrum half Tomas O'Leary as he turned to touch down.
But the lively flanker would not be denied and, after Faletau drove from a maul close to the Munster line, Thomas got the ball and drove over under a pile of bodies from two metres out.
Worse was to come for Munster as they went down to 13 men when number 8 James Coughlan was sin-binned for going offside at a ruck.
Helped by an advancing pack, Tovey regained the 14-point advantage with a penalty near half-time after opposite number Paul Warwick booted a 20-metre penalty for Munster's first points of the game.
But Munster are not perennial league contenders for nothing and they came out firing for the second half.
They had the home team on the back foot for the third quarter but only added a Warwick penalty to their total, although they were helped when home skipper Tom Willis was yellow carded – also for being off his feet at a ruck.
But Munster could not take advantage of the extra man and the Dragons restored their 14-point advantage when Tovey booted a 30-metre drop goal on 66 minutes which meant Munster would need two converted tries to draw.
The visitors had one or two chances, the best being when full-back Scott Deasy kicked over the home defence – but a superb cover tackle from opposite number Pat Leach denied the try.
And, while the table toppers laid siege to the Dragons' line in the final moments, the Welshmen held firm and denied their opponents any chance of a losing bonus point – delighting the majority of the 5,079-strong crowd in the process.