Last time around it was the Blues Welsh neighbours Scarlets who inflicted the damage though on that occasion there was the ever so slight consolation of a losing bonus. On Saturday however, in front of a near full house, there was no consolation whatsoever either in terms of the points table or overall performance.

Rob Penney's side did create chances but unforced errors destroyed any potential return and even at the end as they chased the score that might have given them a point, they again produced the mistake that allowed the Blues clear their lines.

It was all square at the end of the opening half, Ronan O'Gara and Rhys Patchell swopping penalties with the Welsh denied a try, after they broke out of their own 22, when Donncha Ryan managed to thwart Patchell as he looked to gather with the tryline beckoning.

By half time Munster had lost Conor Murray and Mike Sherry to injury and three minutes into the second half they went 10-3 behind after coughing up possession near half way for Williams to score and Patchell add the extras.

By this stage the fog had drifted over Musgrave Park to give a surreal aspect to proceedings that mirrored Munster's display. They had enough possession thanks to a solid set piece yet allowed the Blues to easily marshal their defence.

And it was the visitors who looked to have scored the deciding try when Jamie Roberts made inroads down the Stand side only to save Munster's bacon by throwing a forward pass to Williams with the line at his mercy.

The respite was brief because minutes later the impressive Copeland galloped over for a try and with Patchell adding the conversion it left Munster two scores behind.

Munster: F Jones; D Howlett, K Earls (C Laulala 58 mins), J Downey, D Hurley (I Keatley 59 mins); R O'Gara, C Murray (D Williams 14 mins); D Kilcoyne (W du Preez 75 mins)), M Sherry (S Henry 23 mins), S Archer (BJ Botha 61 mins); D Foley ( B Holland 58 mins), D Ryan; T O'Donnell (CJ Stander 61 mins), S Dougall, J Coughlan.

Cardiff Blues: J Tovey; O Williams, R Smith, J Roberts, H Robinson; R Patchell, L Jones; S Hobbs, R Williams, B Bourrust: B Davies, L Reed; J Navidi, S Warburton, R Copeland. Replacements: K Dacey, P Tamba, S Andrews, J Down, L Hamilton, A Walker, C Sweeney, L Halfpenny.

Referee: Nigel Owens