First-half goals from David Norris and Jason Scotland gave Town a winning end to Championship football at Portman Road this season.
Scotland moved into double figures for the campaign with a left foot finish early on and skipper Norris doubled the advantage and nudged ahead again at Blues' top scorer with his 11th of the term.
Town could have sealed the win before the break, Ronan Murray twice denied by Iain Turner but Preston were a different side in the second-half and could and have more to show for their efforts than Paul Coutts' 52nd minute goal.
Town made five changes to the side that went down at Swansea, Troy Brown coming in for his first start since January with Jimmy Bullard returning to the side after missing the defeat at the Liberty Stadium.
Brown first touch of the ball saw him pick up a yellow card for a foul on Keith Treacy, Daniel Devine heading Barry Nicholson's free-kick wide in what turned out to be the visitors' clearest chance of the first-half.
Marton Fulop, restored to the side, held firm from Treacy's cross before Town got the breakthrough on nine minutes, Josh Carson escaped down the left and from his cross, Scotland buried the ball into the bottom corner.
Preston's main threat came from Treacy, his shot blocked by Damien Delaney but Blues stuck again on 18 minutes, Murray was denied by Turner after Bullard's pass but Norris rattled in the rebound.
Treacy was replaced by Jamie Proctor in a forced change for Phil Brown's side on the half hour.
Billy Jones' scuffed shot was cleared as North End looked for a way back into the game but Town continued to look the more likely to add to the scoreline, Grant Leadbitter firing wide from Carlos Edwards' cross, Bullard testing Turner with a 35 yard free-kick from the angle, then Carson blasting over.
Murray had a gilt edged chance to add a third but Turner saved again with his feet to keep his side still in the game at the break.
Paul Hayes replaced Chris Brown for the start of the second-half and within seven minutes of the restart, North End had reduced the arrears, Coutts' low drive beating Fulop into the far corner.
Coutts weaved his way into the box before Brown came to the rescue, the midfielder then exploding a shot over the bar as Preston threatened to get back on level terms.
Blues responded, Carson firing wide, while at the other end Brown was in the right place to clear as Hayes looked to pounce.
Fulop produced a terrific save to keep out Barry Nicholson as Preston looked a different side in the second-half, Danny Mayor then booked for a foul. Bullard sending the free-kick over.
Murray made way for Andy Drury midway through the half, the former Luton player sending in a terrific cross with his second touch, Bullard failing to keep the ball down from his follow up shot, Turner holding firm.
Adam Barton was replaced by Doyle Middleton for the last 20 minutes, Fulop holding on from Jones' shot, then denying Proctor from close range.
Edwards couldn't hit the target with a right foot effort after running the length of the pitch with the ball at his feet. Town made a second change with Jaime Peters on for Carson - perhaps to the loudest roar of the afternoon. Luca Civelli then following for Scotland.
Town saw out the game and the points with a few alarms over the closing stages as Portman Road bid farewell to another season.
Town: Fulop, Edwards, Brown, Delaney, Kennedy, Carson (Peters 84), Norris, Bullard, Leadbitter, Scotland (Civelli 86), Murray (Drury 65). Subs not used: Murphy, Eastman, Healy, Civelli, Whight. Booked: Brown.
Preston: Turner, Leather, Morgan, Devine, Jones, Coutts, Nicholson, Barton (Middleton 69), Mayor, Treacy (Proctor 28), Brown (Hayes 46) Subs not used: Arestidou, Miller, Carter, Clucas. Booked: Mayor.