Two Paul Warwick penalties and a superb 26th minute try from Felix Jones saw them take a 11-6 lead but it was short lived, Ludovic Mercier orchestrating the move that ended in a try for Julien Laharrague seven minutes from the end of the first half.
Munster upped the pace from the restart and Ronan scored the first of his brace in the 45th minute. Three minutes later it was Buckley who applied the finishing touches to more good forward momentum and although Mercier kept Aironi clinging on with a 54th minute penalty, Warwick cancelled that out with a smartly taken drop goal from line-out ball secured by Billy Holland.
Another Mercier penalty followed but then Doug Howlett's searing break set Johne Murphy racing for the line only to be denied by a last gasp tackle. Support however was quick to arrive with Ronan diving over to score and Warwick adding the extras.
Munster: F Jones; D Howlett, J Murphy, S Tuitupou, I Dowling; P Warwick, P Stringer; W du Preez, D Varley, T Buckley, M O'Driscoll, B Holland; D Ryan, N Ronan, D Leamy capt. Replacements: D Fogarty, M Horan, J Hayes, A Quinlan, P O'Mahony, D Williams, S Deasy, D Barnes
Aironi Rugby: Julien Laharrague; Giulio Rubini, Roberto Quartaroli, Dylan Des Fountain, Giulio Toniolatti; Ludovic Mercier, Tito Tebaldi; Alberto De Marchi, Fabio Ongaro, Salvatore Perugini; Carlo Del Fava, Quintin Geldenhuys; Jaco Erasmus, Gareth Krause, Nick Williams. Replacements: Andrea De Marchi, Roberto Santamaria, Luigi Milani, Marco Bortolami, Aldo Birchall, Michael Wilson, Alberto Benettin, Gabriel Pizarro.