Ulster opened their European campaign with an essential 30-6, bonus point win in Pool Four's opening clash stretching their unbeaten run to six games in all competitions.
But the win did not come easy for Brian McLaughlin's side, who showed lack of composure in a lacklustre first half which only saw the home side lead 11-6 despite Aironi playing out the last 10 minutes with 14 men.
The second half saw Ulster stretch away and Andrew Trimble's first half try was supplemented by scores from Ian Humphreys, Simon Danielli and Ruan Pienaar to give Ulster maximum points ahead of next week's second round in Biarritz.
Looking to get tries on the board, Ulster immediately attacked after receiving the kick-off and with Jamie Smith and Ruan Pienaar prominent in the sweeping attack, Ulster took play up into Aironi's 22 where Pienaar landed a first minute penalty.
Four minutes later, though, Ludovic Mercier tied the scores after some crossing from Ulster and was then wide with a long range effort after Ulster collapsed a maul. But Pienaar was then also off target with a 30-metre effort which came off the upright before Mercier slotted his second to give the Italians a three-point lead.
This fired Ulster into life and, just after Trimble was penalised for receiving a forward pass on a diagonal run, Ulster produced a huge shove at the scrum and shunted the visitors off the ball. Robbie Diack picked up and fed Pienaar, whose superb flick pass found Trimble and he steamed over in the corner. Despite narrowing the angle for Pienaar, the Springbok was wide with the extras.
Ulster kept pressing and Johann Muller came close which resulted in Marco Bortolami being binned for killing the ball. However, the home side failed to take advantage and spilled a number of scoring chances before Pienaar slotted his second penalty just as Bortolami returned to give Ulster an 11-6 lead at the interval.
They needed a quick score in the second half and got one thanks to some sloppy work from Nick Williams, who failed to deal with a Humphreys kick to the left corner which allowed the Ulster outside-half to run up and touch the ball down as Williams looked on helplessly. The angle was too tight for Pienaar's conversion but Ulster now had a 10-point lead.
On the hour mark, Ulster got their third score after Chris Henry snaffled the ball back after Aironi had stolen a lineout and launched an attack up the right with Muller and Best. The ball was quickly recycled and spun left where Danielli juggled it before diving over.
Humphreys slotted an excellent touchline conversion and then seven minutes later, the bonus point arrived after great work from Diack allowed Pienaar dart over to the right of the posts, Humphreys' conversion taking the score to 30-6.