Ulster scored six tries in securing the bonus point win they needed away to Aironi in the Heineken Cup.
The Irish province are now top of Pool Four, two points ahead of Leicester.
Winger Andrew Trimble got Ulster's first try in the sixth minute and that was followed by a penalty try and Tom Court's touchdown in the first half.
Sinoti Sinoti and Roberto Quartaroli tries revived Aironi before Ulster scored through Craig Gilroy, Robbie Diack and Adam Macklin.
Brian McLaughlin's men now face crunch clashes at home to Leicester and away to Clermont.
Ulster opened brightly in Monza and should have had a try after just four minutes but Trimble somehow lost control of the ball when attempting to ground it with his right hand.
However, the Ireland winger quickly made up for that slip by just about scoring under the posts, giving Ian Humphreys an easy conversion for 7-0.
Humphreys and Luciano Orquera traded penalties before Ulster were awarded a penalty try after their rolling maul was dragged down just short of the hosts' line.
The Ulster number 10 maintained his fine kicking with the conversion and a penalty.
Court crossed for Ulster's third try and the conversion by Humphreys meant a 24-point half-time cushion.
The extra point seemed a formality but Aironi summoned a commendable response in the second half.
Sinoti slipped in for a 56th-minute try after a period of sustained pressure, with Orquera adding the extras.
A game that was effectively dead at half-time burst into life when replacement Quartaroli sprinted home from 70 metres for Aironi's second
Ulster looked to be struggling to get that all-important fourth try until winger Gilroy got in at the left corner 10 minutes from time.
Aironi replacement George Biagi scored a late consolation try, but Diack and Macklin both touched down to finish off a workmanlike performance for Ulster, whose only concern was a knee injury picked up by young replacement Paddy Jackson.
Aironi: Trevisan, Sinoti, Masi, Pizarro, Venditti, Orquera, Keats, Perugini, Ongaro, Romano, Geldenhuys, Bortolami, Cattina, Favaro, Sole.
Replacements: Quartaroli for Trevisan (48), Olivier for Orquera (61), Tebaldi for Keats (61), A. De Marchi for Perugini (41), D'Apice for Ongaro (46), Staibano for Romano (46), Biagi for Geldenhuys (46).
Not used: Ferrarini.
Ulster: D'Arcy, Trimble, Cave, Spence, Gilroy, Humphreys, Pienaar, Court, Best, Afoa, Muller, Tuohy, Ferris, Henry, Wannenburg, Jackson.
Replacements: Terblanche for Trimble (49), Jackson for Spence (46), P. Marshall for Humphreys (65), McAllister for Court (49), Macklin for Afoa (78), Barker for Tuohy (61), Diack for Wannenburg (65), Brady for Jackson (67).