Replacements used: Ailis Egan (Old Belvedere/Leinster) for Bourke (50 mins), Paula Fitzpatrick (St. Mary's/Leinster) for Fleming, Larissa Muldoon (Bristol/Exile) for Davis (both 60), Jenny Murphy (Old Belvedere/Leinster) for Cantwell (63), Hannah Casey (Saracens/Exiles) for Miller, Jackie Shiels (Richmond/Exile) for Briggs (both 69), Fiona Hayes (UL Bohemians/Munster) for Kennedy, Kerrie-Ann Craddock (Saracens/Exile) for Coghlan (both 76).
Replacements used: Sofia Stefan (Rennes) for Veronese (61 mins), Lucia Cammarano (Rugby Monza) for Ferrari (64), Debora Ballarini (Sitam Riviera del Brenta) for Coulibaly, Elisa Giordano (Valsugana Padova) for Arrighetti (both 69), Maria Magatti (Rugby Monza) for Sillari (70), Irene Campanini (Rugby Colorno) for Bettoni, Alessia Pantarotto (Sitam Riviera del Brenta) for Trevisan, Monica Bruno (CUS Torino Rugby) for Rigoni (all 77).
That St. Patrick's Day fixture in Parabiago, Milan was played in extremely hazardous conditions and following a dogged display from the visitors, a first ever title was won with three points to spare over the Italians (6-3).
The weather was far more favourable at Lansdowne Road for the latest meeting of the teams however, and having seen a seven-game winning run come to an end against England at Twickenham, Ireland were eager to avoid a second straight defeat in this year's tournament.
Though expectations were high ahead of a massive occasion for the hosts, Andrea di Giandomenico's outfit were not to be dismissed lightly and like Ireland, they had two wins against Wales and Scotland under their belts prior to this historic clash which was played out in front of just over 5,500 supporters.
Playing in the immediate aftermath of Brian O'Driscoll's emotional final home appearance in an Ireland shirt, the Fiona Coghlan-led Women's side started the game with plenty of intent.
With just five minutes on the clock, full-back Niamh Briggs made no mistake with a well-struck penalty goal.
The score settled some early Irish nerves but there was no reason for the Italians to panic and they started to apply some pressure of their own inside the Irish half.
Indeed, a smart cross-field move almost resulted in a try for Benetton Treviso's Manuela Furlan, but the final pass by out-half Veronica Schiavon did not reach its intended target.
As the first quarter developed, Italy continued to display plenty of industry, but the watertight Irish defence eventually weathered this particular storm.
Good work on the ball by Connacht's Alison Miller set a second penalty attempt for Briggs, but this time her effort came crashing back off the woodwork and away to safety.
It was only temporary respite for the Italians though and after Briggs added to her account with a 28th minute penalty, Ireland inevitably crossed for the contest's opening try.
Nora Stapleton and lively prop Gillian Bourke did the spade work and having evaded a number of forlorn tackles, quick-witted flanker Claire Molloy picked a great line to touch down in spectacular fashion.
With Briggs comfortably converting from close range, Ireland were now firmly in command.
Just two minutes before the interval, a second converted try from Lynne Cantwell left Italy with an even greater task on their hands. The 82-times capped centre's diagonal burst took her over the line along with a neat dummy.
That gave the girls in green a 20-0 half-time lead and the final outcome was put beyond any doubt nine minutes into the second half.
Miller had been outstanding for Ireland on the left wing during the opening period, posing a constant threat for the Italian defence. She got the try that her performance deserved at the end of a typical surging dash towards the line.
In adding to her already impressive international scoring record, Miller, who is a daughter of former Laois GAA star Bobby, showcased an abundance of physical strength by shaking off a series of attempted Italian tackles.
Shortly after the third try, head coach Doyle opted to dip into his replacements with next week’s crunch encounter with France no doubt in the back of his mind.
This should have given Italy an incentive to finally open their account for the evening, but it only served to re-energise their ever-improving hosts.
Ireland's fourth try of the night came from an Italian scrum inside their 22 and after Ireland had forced a turnover, number 8 Heather O'Brien picked up the loose ball and drove over the whitewash - as she had done earlier in the campaign against Wales.
By this point, the Italians were completely deflated and starved of territory. Ireland duly put the icing on the cake with a try from replacement Jenny Murphy right at the death.
Nora Stapleton, taking over the kicking duties from the departed Briggs, expertly slotted the conversion with Irish thoughts already turning to next Friday's concluding game in Pau.
Ireland are currently top of the table on scoring difference from England - +99 compared to +90 - although France, who have three wins from three, will go two points clear if they beat Scotland away tomorrow.
Referee: Leah Berard (USA)