Preston regained their place in the top six by completing the double over the Tractor Boys.
Richard Naylor was sent off after 10 minutes after being the last man and bringing down Brett Ormerod after he had been put through by David Nugent.
Paul McKenna hit the resulting free-kick from 20 yards against the left-hand post.
Ormerod had a shot saved by the Ipswich keeper from a right-wing corner and Town boss Joe Royle had to rearrange his side with a tactical substitution of Luis Sito for Darren Currie after just 14 minutes and then later Ian Westlake came on for Jimmy Juan.
Jason De Vos headed Ipswich into the lead after 38 minutes with an eight-yard header into the bottom corner of the net from a free-kick by Owen Garvan.
Nugent equalised for Preston after 53 minutes with a right-foot shot into the bottom corner of the net from 15 yards after a pass by Ormerod.
Ricardo Fuller was replaced by Danny Haynes after 56 minutes and Nugent made it 2-1 to Preston with a 12-yard volley into the top corner of the net after a cross by Ormerod.
Nugent twisted his ankle and had to be replaced by Daniele Dichio and the other substitute Patrick Agyemang raced down the left and hit a 15-yard shot under the keeper and into the bottom corner of the net from a pass by McKenna to make it three and wrap up the points.