Leicester Tigers opened their Heineken Cup account with a 28-12 win over Aironi but failed to capture the all-important bonus point in Monza on Saturday.
The two-time Heineken Cup winners scored two tries in the first half through Tom Croft and Alesana Tuilagi before Niall Morris dotted down for his fourth try of the season late in the second half.
The rest of the points came from Toby Flood, who became only the third Tigers player to score 200 Heineken Cup points for the club after Andy Goode and Tim Stimpson.
A break by Morris had Tigers on the front foot early in the game. He was well supported by Matt Smith but the centre looked for contact when it seemed Geordan Murphy was well placed on his inside.
However, Aironi were pinged at the breakdown and Flood made no mistake with the penalty to kick the Tigers into a 3-0 lead after two minutes. Flood doubled the lead in the fifth minute with his second penalty after Aironi had come through a line-out.
Aironi were guilty of conceding a string of penalties in the opening stages and referee Neil Paterson lost his patience in the eighth minute, giving Sinoti Sinoti a yellow card after the wing was ruled offside.
Leicester almost took instant advantage when they worked an opening on the left but Murphy was unable to gather Smith's pass and the chance went away.
They were getting plenty of joy down the Aironi right and it was from this flank that they scored the game's first try after 13 minutes. Flood and Alesana Tuilagi combined to give Croft a free run to the corner for his fifth Heineken Cup try and Flood's extras gave Tigers a 13-0 lead.
Tigers were on top in the opening quarter pinning Aironi back in their own half. The visitors created opportunities on the right flank for Forsyth and then Smith but scrambled Aironi defence managed to keep Tigers out until the end of Sinoti's sin-binning.
Moments after the wing returned to the field, the Tigers had their second try. Again Flood was involved, his inside pass finding Tuilagi on the charge and the Samoa international forced his way over. Flood's extras gave Leicester a 20-0 lead.
Aironi's first real foray into the Tigers half gave them their first opportunity of points when Tigers went offside. Fly-half Luciano Orquera landed the penalty to leave Leicester 20-3 ahead after 23 minutes.
The penalty lifted the home crowd, and they raised the noise levels further when tackles on Flood and Tuilagi resulted in another penalty for the hosts for holding on. Orquera doubled Aironi's tally with his kick from close to halfway.
Leicester finished the half deep in Aironi territory, probing for an opening. Forsyth came close to creating it, breaking Andrea Masi's tackle but his offload was intercepted by the retreating Fabio Ongaro and Orquera was able to clear to touch for the last action of the half.
The Tigers had a chance to extend their lead two minutes after the restart but Flood's penalty struck the right post and Aironi were able to clear.
Flood made no mistake with a second penalty five minutes into the half, kicking Tigers 23-6 ahead. But moments later Aironi cut the lead by three points through Orquera's third penalty of the game.
It was a scrappy period of play. One promising Tigers attack ended with a knock-on on the edge of the Aironi 22. Then, at the other end, Tyson Keats's kick ahead bounced up for Quintin Geldenhuys, but the lock knocked-on in trying to gather possession.
The third quarter saw Leicester called on in defence as Aironi enjoyed plenty of territory. Castrogiovanni replaced Cole for his 50th Heineken Cup appearance but the hosts were not about to give him an easy ride.
They kicked to the corner with a number of second-half penalties in the Tigers half, but were unable to find a way through as Leicester defended the catch and drive well. Eventually they opted to kick at goal when Thomas Waldrom was pinged at a ruck and Orquera's fourth penalty cut Leicester's lead to 23-12 with 10 minutes left.
Leicester pressed from the restart with Marcos Ayerza and Smith finding gaps in the Aironi defence. However, with Tuilagi in space on the left, the final pass went to ground and the chance went away.
The Tigers scored their third try right on full-time when Murphy's long pass cut out a couple of Aironi defenders to find Morris in space to dot down in the right corner. Flood was unable to add the extras with the last kick of the game.
Pens: Orquera 4
For Leicester Tigers:
Tries: Croft, Morris, Tuilagi
Cons: Flood 2
Pens: Flood 3
Aironi: 15 Ruggero Trevisan, 14 Sinoti Sinoti, 13 Andrea Masi, 12 Matteo Pratichetti, 11 Giovanbattista Venditti, 10 Luciano Orquera, 9 Tyson Keats, 8 Frans Viljoen, 7 Simone Favaro, 6 Nicola Cattina, 5 Marco Bortolami, 4 Quintin Geldenhuys, 3 Fabio Staibano, 2 Fabio Ongaro, 1 Salvatore Perugini.
Replacements: 16 Roberto Santamaria, 17 Matias Aguero, 18 Lorenzo Romano, 19 Josh Sole, 20 Filippo Ferrarini, 21 Giorgio Bronzini, 22 Naas Olivier, 23 Gilberto Pavan.
Leicester: 15 Geordan Murphy, 14 Niall Morris, 13 Matt Smith, 12 Andy Forsyth, 11 Alesana Tuilagi, 10 Toby Flood, 9 Sam Harrison, 8 Thomas Waldrom, 7 Jules Salvi, 6 Tom Croft, 5 Geoff Parling, 4 Louis Deacon, 3 Dan Cole, 2 George Chuter, 1 Marcos Ayerza.
Replacements: 16 Tom Youngs, 17 Boris Stankovich, 18 Martin Castrogiovanni, 19 George Skivington, 20 Steve Mafi, 21 Micky Young, 22 Jeremy Staunton, 23 Scott Hamilton.
Referee: Neil Paterson (Scotland)