England remain on course for back-to-back Six Nations grand slams but celebrations will be muted after they produced their worst performance under Eddie Jones.
RNZ reports it is a 17th game unbeaten for England who can draw level with the All Blacks record of 18 when they take on Scotland in their next Six Nations game.
England were all over the place in an error-strewn first half and though Dan Cole bundled over the line in a rare attack to put them 5-0 up they were lucky to reach the break 10-5 down after Giovanbattista Venditti scored a try for Italy after an earlier Tommaso Allan drop goal.
England came out firing with quick-fire tries for Danny Care and Elliot Daly but Michele Campagnaro blasted through some lightweight defending to get Italy back within two points.
It proved a false dawn, however, as Jack Nowell crossed for the fourth, bonus-point try, followed soon afterwards with a fifth for Ben Teo, with Nowell finishing things off with his second in the last minute.
England top the standings on 13 points after three wins. Ireland, who beat France yesterday, are second on 10 points with Scotland third on nine following their home win over Wales, who are fourth on five points.