A Martin Paterson strike just before half time was enough to earn Scunthorpe a vital victory at Deepdale on Boxing Day.
The Iron's hot-shot took his total for the season to 11 with his strike also ending North End's two-match winning streak following successes on the road at Burnley and Southampton.
The Lilywhites could not find the luck or quality in the final third to break down a resilient Scunthorpe side that defended extremely well for long periods in a match that was only really brought to life following the only goal on 42 minutes.
The defeat means that the men from North Lincolnshire leapfrog Preston as North End slipped back in the relegation zone with only Colchester below them in the Championship table.
Prior to kick-off North End were boosted by the news that Paul McKenna was fit to take his place in the midfield. The influential skipper had been forced to sit out the trip to St Mary's but his presence in the centre of the park had hoped to add that extra bit of steel to Alan Irvine's starting XI.
In the opening five minutes Scunthorpe were handed the opportunity to take an early lead when Matt Hill was caught out of position. Luckily for the left-back Paul Hayes failed to divert Kevan Hurst's cross past Andy Lonergan, or even on target as a matter of fact.
You would have thought the early scare would offer a spark to North End but it took a deflected Andy Paterson effort moments later to get the PNE players going. The former Stoke City man found himself unmarked 10 yards out but his tame right-footed effort ricocheted off Liam Chilvers, forcing Lonergan to save with his legs.
PNE broke immediately as Gallagher, Sedgwick and McKenna combined down the right but Simon Whaley couldn't make the most of the captain's deep cross.
Not much goalmouth action followed in a quiet opening 20 minutes apart from Ian Baraclough becoming the first name in the referee's notebook for a tug on Neil Mellor when the former Liverpool man was away down the right flank. In an enforced change, Darren Carter took the place of Billy Jones who departed the Deepdale turf with a problem relating to his withstanding hernia, meaning Callum Davidson had to revert to right-back.
Paul Hayes flashed wide midway through the half, Jim Goodwin saw an optimistic long range effort sail high over the bar whilst Jack Cork hit an angled left-footed daisy cutter that rolled across the face of Andy Lonergan's goal. Although all the attempts were relatively weak, Scunthorpe were offering the most going forward out of the two teams.
The Lilywhites best attempt of the half was foiled by a combination of Joe Murphy and the linesman's flag. The two Pauls, Gallagher and McKenna, linked up well on the edge of the box but as the ball was threaded through to Neil Mellor, who forced a decent stop from the Iron's stopper, the official raised his yellow flag.
The first and last goal came about when Matt Hill and Sean St. Ledger collided on the edge of box, allowing Paterson a run on goal from a long deep ball down the Scunthorpe right. The pacey number 10 took the ball five yards forward before cooling slotting under Andy Lonergan from a slight angle.
The goal kick-started PNE in the minutes before the break as Simon Whaley hit the post after being set up by a short Darren Carter assist. The winger's thudding shot cannoned back off the left-hand upright and as the ball bounced out to the onrushing Chris Sedgwick, the midfielder blazed over the bar from a similar position to which he netted the equaliser against Burnley a couple of games prior.
No changes by either manager were deemed necessary at the interval as North End came out of the traps the livelier as they sought the equaliser. Paul Gallagher got himself into a goalscoring position five minutes after the restart but rather unselfishly, he let his fellow attacker Neil Mellor take aim, Crosby coming to the rescue only seconds before the number 33 seemed destined to pull the trigger and find the net.
Callum Davidson nearly scored a spectacular 20 yard own goal moments later when he made Andy Lonergan palm wide before Simon Whaley, on a typical dribble from the left, cut in and fired only inches wide of the far post.
There had been more action in the opening ten minutes than the entire first half.
Nigel Adkins opted for a change taking Paul Hayes off in a tactical reshuffle that saw Matt Sparrow enter the fray in a five man Scunthorpe midfield.
Paul Gallagher, in the last week of his loan spell was instrumental in everything PNE created as Alan Irvine decided on the hour mark that it was time for super sub Pat Agyemang to be introduced. Uncannily, it was only seconds before he had an effect, teeing up Gallagher who made Joe Murphy in the Scunthorpe goal turn a placed side foot shot round his left hand post from ten yards out.
The fans in the Town End rallied as Agyemang's pace forged another opening for the assertive North End when his twist and cross almost resulted in Cliff Byrne slicing through his own net on 67 minutes.
Neil Mellor scuffed a shot from the edge of the box, Simon Whaley thrashed at a volley and Paul Gallagher's 30 yard arrow flew wide but still North End continued to press in search of the leveller.
However, they were thwarted by Scunthorpe's last ditch tactic of getting men behind the ball much to the frustration of the majority of the 12,920 supporters in Deepdale.
In the last minute Paul McKenna smashed one just over the bar from all of 35 yards but it was the closest Preston were to come as despite the four minutes of injury time being played, in which Cliff Byrne was dismissed for two bookables, Scunthorpe hung on for a crucial three points on their behalf.
PNE: Lonergan, Jones (Carter 21), St. Ledger, Chilvers, Hill (Lewis Neal 88), Sedgwick (Agyemang 63), McKenna, Davidson, Whaley, Mellor, Gallagher.
Subs Not Used: Chris Neal, Hawley.
Scunthorpe: Murphy, Byrne, Crosby, Baraclough, Williams, Cork, Goodwin, Hayes (Sparrow 57), Morris (Ameobi 69), Hurst, Paterson (Forte 78).
Subs Not Used: Lillis, Taylor.
Sent Off: Byrne (90).
Booked: Baraclough, Byrne.
Goals: Paterson 42.
