The Ospreys sealed a 38-6 bonus point Magners League victory but they made heavy weather of seeing off Aironi at the Liberty Stadium.
The Welsh region ended up scoring five tries to nil but the bonus score did not come until 15 minutes from the end. The victory puts the Ospreys up to fifth in the league.
The Ospreys scored tries through wing Richard Fussell, Lee Byrne, centre Tommy Bowe and two by way of penalty tries.
The Ospreys led 24-6 at half-time with three tries but it was a largely frustrating 40 minutes for the Welsh side.
They had a wealth of possession but too many mistakes crept into their play as well as the fact that play was held up for 10 minutes while flanker Ben Lewis had treatment to a serious-looking neck injury. He was taken from the field by stretcher.
The Ospreys looked on their way to a comfortable victory as early as the seventh minute when Fussell crossed after the home side had won good ball at a line-out from their captain Alun Wyn Jones.
But after that, dropped balls and forward passes stopped the Ospreys completely dominating the scoreboard. Fly-half Dan Biggar did put over a penalty goal on 18 minutes but that was immediately cancelled out by his opposite number Riccardo Bocchino.
It took the sin-binning of flanker Josh Sole, who tackled Jerry Collins off the ball,
to open the way for the Ospreys' second try. That came with a penalty try after the Italian side were penalised three times at a five-metre scrum.
Bocchino closed the gap briefly with a penalty goal from near halfway but the Ospreys finished the half with a converted try for Byrne, who was put over by fellow British Lion Shane Williams.
It was a very uninspiring first quarter as the Ospreys failed to register any further scores and it took the sin-binning of former Italy captain Marco Bortolami for the Welsh side to be awarded a penalty try on 65 minutes.
That took the pressure off for the Ospreys, who went in for a fifth try four minutes later when Bowe crossed after a break up the middle of the field by number eight Jonathan Thomas.
Tries: Fussell, Penalty Try 2, Byrne,Bowe
Cons: Biggar 4, Owen
Pens: Bocchino 2
Ospreys: 15 Lee Byrne, 14 Richard Fussell, 13 Tommy Bowe, 12 Andrew Bishop, 11 Shane Williams, 10 Dan Biggar, 9 Jamie Nutbrown, 8 Jonathan Thomas, 7 Ben Lewis, 6 Jerry Collins, 5 Alun Wyn Jones (c), 4 Ian Gough, 3 Adam Jones, 2 Richard Hibbard, 1 Paul James.
Replacements: 16 Huw Bennett17 Ryan Bevington18 Craig Mitchell19 Ryan Jones20 Justin Tipuric21 Mike Phillips22 Gareth Owen23 Nikki Walker
Aironi: 15 Danwel Demas, 14 Giulio Toniolatti, 13 Gilberto Pavan, 12 Gabriel Pizarro, 11 Giulio Rubini, 10 Riccardo Bocchino, 9 Michael Wilson, 8 Gareth Krause, 7 Josh Sole, 6 Andrea Benatti, 5 Quintin Geldenhuys (c), 4 Marco Bortolami, 3 Luca Redolfini, 2 Luigi Ferraro, 1 Salvatore Perugini.
Replacements: 16 Leonardo Ulises Gamboa, 17 Fabio Ongaro, 18 Alberto De Marchi, 19 Joshua Furno, 20 Nicola Cattina, 21 Pablo Canavosio, 22 Julien Laharrague, 23 Alberto Benettin.
Referee: Andy Macpherson (Scotland)