Ireland struggled for the majority of the game, and it was 3-3 at half-time. But Leah Lyons, Sophie Spence, Paula Fitzpatrick and Tyrrell touched down in the second- half.
Ireland coach Tom Tierney had made two changes to his side after their thrilling last-minute victory over Scotland last weekend. Elaine Anthony came into the second row, while Sevens star Tyrrell was given her place on the right wing.
Despite perfect conditions for rugby, the first-half was littered with errors from both sides. Ireland centre Sene Naoupu was guilty of knocking on an numerous occasions, and Ireland couldn’t convert their dominance into points.
Alison Miller almost scored when she broke down the left wing in the 20th minute, but she was caught short of the Italian line by scrum-half Sara Barrattin.
And, one minute later, Ireland hooker Lyons was held up over the Italian whitewash. Both sides turned down kickable penalty chances in the early stages, but the visitors took the lead in the 28th minute when Nora Stapleton slotted her first penalty.
Italian wing Michela Sillari responded in kind just before half-time, and on the resumption, Ireland messed up another chance when Mairead Coyne knocked on with the Italian line at her mercy. Eventually it clicked for Ireland.
Lyons touched the ball off the base of the post for the first try in the 51st minute. And, after Stapleton converted, Ireland came back up the pitch and Spence touched down.
Stapleton’s second conversion gave Ireland a 17-3 lead in the 56th minute and captain Fitzpatrick put the game beyond doubt with their third try after the hour, and Tyrrell sealed the bonus point at the end.
Pen: M Sillari.
Try: L Lyons, S Spence, P Fitzpatrick, H Tyrrell. Pen: N Stapleton. Con: N Stapleton (2).
M Furlan; M Sillari, M Cioffi, S Stefan, M Magatti; B Rigoni, S Barattin; E Cucchiella, M Bettoni, L Gai; F Severin, A Trevisan; L Cammarano, I Locatelli, E Giordano.
P Zangirolami for Cioffi (39), M Ferrari for Cucchiella (42), I Arrighetti for Gai (50), E Pillotti for Locatelli (55), M Este for Severin (60), G Giacomoli for Bettoni (75), C Salvadego for Magatti (75).
M Coyne; H Tyrrell, J Murphy, S Naoupu, A Miller; N Stapleton, A Hughes; L Peat, L Lyons, A Egan; E Anthony, ML Reilly; C Griffin, C Molloy, P Fitzpatrick.
C McLaughlin for Murphy (38, HIA), Murphy for McLaughlin (40), S Spence for Anthony (40), M Healy for Hughes (40), C Cooney for Griffin (62), I van Staden for Peat (74), C O’Connor for Egan (74).
Rachel Horton (Australia).