Aironi (6) 6 Pen: Tebaldi Drop: Marshall Ulster (10) 43 Tries: Trimble, Wannenburg 2, penalty try, Henry, Danielli Cons: Humphreys 5 Pen: Humphreys
Ulster centre Nevin Spence is tackled by Aironi's Vickus Liebenberg
Ulster have qualified for the quarter-finals of the Heineken Cup for the first time in 12 years thanks to a fine six-try win away to Aironi.
Ireland winger Andrew Trimble scored the only try of a scrappy first half to give the visitors a 10-6 interval lead.
Pedrie Wannenburg got two tries early in the second half as Ulster powered over from a couple of rolling mauls.
Ulster scored three more tries through a penalty try, replacement forward Chris Henry and Simon Danielli.
The other 13 points came from the left boot of fly-half Ian Humphreys.
Ulster had gone into the game needing just the win to get out of the group stages for the first time since 1999 when they won the European Cup.
They quickly edged ahead through a Humphreys penalty and looked to be well on their way when full-back Adam D'Arcy cut through and fed Trimble on the right and he ran on to score under the posts.
Ulster were 10-0 up but were guilty of a series of mistakes and Aironi cut the deficit through a James Marshall drop goal and a penalty kicked by Tito Tebaldi.
A strong start to the second half saw Ulster take command of the Pool Four fixture.
In the first minute of the half, a well controlled maul and Ulster charge resulted in number eight Wannenburg getting the try.
A similar tactic soon brought South African Wannenburg his second try and the required victory appeared to be in the bag.
Ulster were keen to wrap up the bonus and, when awarded a penalty, they opted to go for the line-out instead of the posts.
Their initial drive was held up short but, from the resulting scrum, Aironi's pack crumbled and French referee Christophe Berdos walked under the posts to award a penalty try.
It was from another scrum that they grabbed their fifth try, pushing Aironi off their own set-piece, handing Wannenburg a perfect attacking position.
The former Springbok powered forward before off-loading to replacement Henry, who picked his angle to perfection.
Wannenburg was again involved as Ulster sealed the rout with a sixth score, passing to Ian Whitten who shipped on to Danielli, handing the wing an easy finish in the left-hand corner.
Ulster coach Brian McLaughlin:
"We have done brilliantly in our group and it is a great achievement to reach the quarter-finals.
"It is with great pride and great joy that I say that we are where we want to be and we want to kick on now and show people that we deserve to be there.
"We are more than capable of going anywhere in the quarter-finals and turning in a display that will take us who knows where."
Aironi: Laharrague, Canavosio, Penney, Pavan, Pratichetti, Marshall, Wilson, Aguero, Ongaro, Staibano, Bortolami, Geldenhuys, Liebenberg, Erasmus, Sole. Replacements: Bocchino for Laharrague (50), Pizarro for Pavan (48), Tebaldi for Wilson (13), Perugini for Aguero (57), A. De Marchi for Staibano (67), Del Fava for Geldenhuys (57), Birchall for Liebenberg (47). Not used: Santamaria. Ulster: D'Arcy, Trimble, Spence, Wallace, Danielli, Humphreys, Pienaar, Court, Brady, Fitzpatrick, Muller, Tuohy, Ferris, Faloon, Wannenburg. Replacements: Mcllwaine for Trimble (64), Kyriacou for Wallace (67), P. Marshall for Pienaar (66), Barker for Court (67), I. Whitten for Brady (67), Young for Fitzpatrick (57), Cronin for Tuohy (67), Henry for Ferris (57). Att: 2,800
Ref: Christophe Berdos (France)