Second-half goals from midfielders Tommy Miller and Ian Westlake sealed the win against a disappointing visiting side who rarely threatened the home goal.
Town might have gone ahead after just a minute when Jim Magilton collected a Jermaine Wright pass, held off a defender, but fired his shot narrowly over from 14 yards.
Jonathan Gould tipped over a Matthew Richards curling free-kick from 30 yards, but it was a rare effort on target in a poor first half.
The only other moments of note were an easy catch for Ipswich keeper Kelvin Davis from a tame Tyrone Mears header and then a fine diving save from Gould to keep out a low John McGreal strike.
Thankfully the second half was more lively aided by the introduction of subs Richard Naylor for Ipswich and Preston's David Healy.
Naylor immediately earned a free kick from which Magilton tested Gould, before Davis made a magnificent one-handed save to palm aside Richard Cresswell close-range header from a curling Healy corner.
Ipswich went ahead on 72 minutes when Preston cleared a Magilton corner only as far as Westlake whose low drive was turned in from five yards by Miller.
Darren Bent almost fed Naylor only for his strike colleague to fail to connect six yards out, then Claude Davis robbed Bent after Fabian Wilnis had put him clear.
Ricardo Fuller flashed a drive wide and Davis shot over as they chased an equaliser from a game they had been dormant in for so long.
They always looked vulnerable on the break and so it proved in stoppage time when Bent fed Wilnis who picked out Westlake to calmly find the far corner.