Early on, it was Preston keeper Andy Lonergan who denied Ipswich by saving shots from Pablo Counago and Jon Walters, plus a firm header by home skipper Jason De Vos.
Preston threatened for the first time with a 35-yard drive from Callum Davidson which flashed wide, before Billy Clarke wasted a great chance for Ipswich, diving to nod wide from Owen Garvan's free-kick when unmarked.
Town were desperately unlucky on 27 minutes when De Vos nodded Garvan's corner goalwards, Counago's back header went onto the bar and Fabian Wilnis headed the rebound against the post.
Wilnis had two mad moments in front of his own goal before half-time, getting his head onto a Kevin Nicholls free-kick which deflected onto the roof of the net and slicing an attempted clearance over keeper Neil Alexander and narrowly wide.
In between though, Town had taken the lead when Walters crossed from the right and Alan Lee dived low to steer a header past Lonergan despite the goalkeeper getting a decent hand on it on 34 minutes.
After the break, Ipswich continued to look the more lively side, with Walters spearheading a break which ended with Lonergan saving his low shot after a quick exchange of passes with Counago.
Preston wasted a great opportunity just before the hour when a series of corners ended with Nicholls' delivery flashing across goal and Karl Hawley steering it wide from very close range.
Town hit the woodwork for the third time on 63 minutes when Clarke collected a loose ball and thrashed a fierce 25-yard left-footer against Lonergan's left-hand post.
Counago flashed a low drive across goal before his lay-off was drilled home by Tommy Miller from ten yards for his first goal since rejoining Ipswich in the summer.
Preston ensured a nervy finale when substitute Neil Mellor went to ground under challenge from David Wright and Alexander, although the forward looked to be on the way down before any contact was made.
Referee Mike Russell gave the penalty though and Mellor sent Alexander the wrong way from the spot.
But Ipswich held on through five minutes of stoppage time and actually looked the more likely side to score.