Despite a decent final quarter and a penalty try and try from Lifeimi Mafi Munster went down 21-17 to Aironi in the RaboDirect PRO12.

It was just Aironi's fourth win of the campaign but one they fully deserved even if they had their supporters chewing their nails at the close as they clung on to their four point advantage.

And Munster had opportunities to snatch a last gasp win but stout Aironi defence and over anxiousness cost them dearly. Tries from flanker Nicola Cattina and centre Gabriel Pizarro had them leading 15-3 at half time.

Cattina's try came after just seven minutes when he won the chase to a Luciano Orquera kick and their second came just before the break when Pizarro was the beneficiary of powder puff Munster defence, to score beside the posts.

Munster's sole score in that opening half came from a long range Scott Deasy penalty in the 27th minute, but they never once threatened the Aironi line in that opening 40.

Nor were they much better in the third quarter but put themsleves in a position where they might have snatched a win with their best period that ended up being a case of too little too late.

They started brightly and Deasy should really have put them in front but drilled a straight forward penalty wide in the opening minutes and after that it was the home side who made the most of their opportunities.

Cattina beat Denis Hurley to get the opening try safter just seven minutes and then centre Pizarro waltzed past several would be tacklers to score the second just before the break.

Trailing 15-3 Munster had all the time in the world to set matters right but there wasn't much improvement when they returned for the second half and Orquera extended his side's lead with a 48th minute penalty.

It wasn't until Tony McGahan resorted to his bench that the tide started to turn and Marcus Horan, David Wallace and BJ Botha's arrival was soon followed by a penalty try.

That arrived on the hour mark but Orquera kicked a long range penalty six minutes later to leave Munster needing two tries.

Their second came in the 73rd minute from Lifeimi Mafi, Ian Keatley, a half time replacement for Deasy, converting and with just minutes remaining Keatley's crossfield kick was just a little too far for Luke O'Dea to capitalise.

The losing bonus point will have been of little consolation but there was something to cheer about with the return to action of David Wallace and Mike Sherry

The 14 RaboDirect PRO12 points they harvested during the international may seem like a decent return and leaves them in clear second place in the table.

But this was certainly one that they left behind them.

Munster: F Jones; D Hurley, S Tokula (L O'Dea 53 min), L Mafi (I Keatley 27-30 mins), S Zebo; S Deasy (I Keatley 41 mins), D Williams; W de Preez (M Horan 53 mins), M Sherry (D Fogarty 75 min), S Archer (BJ Botha 57min); B Holland, M O'Driscoll (capt); D O'Callaghan (I Nagle 58 min), T O'Donnell (D Wallace 56 min), P Butler.

Aironi: T Tebaldi; R Pavan, M Pratichetti, G Pizarro, S Sinoti; L Orquera, T Keats; M Aguero (A de Marchi 56), R Santamaria (F Ongaro 58), L Romano (S Perugini 58); G Biagi, C del Fava; F Ferrarini, N Cattina, J Sole.

Referee: D Wilkinson.