The contest's only goal came in the 37th minute, Forest breaking forward from their own box after defending a PNE free-kick.
They broke three on two, with Nelson Oliveria applying the finishing touch at the far post.
North End saw plenty of the ball but were often wasteful in possession in and around the Forest box.
They twice came close to an equaliser in the second half though, it needing fine save from home keeper Dorus De Vries to deny the,.
De Vries saved one-handed at the foot of the post to keep out a header from substitute Jordan Hugill.
Later, he threw himself across goal to palm a 20-yard shot from Ben Pearson past the post.
North End's line-up had shown two changes to the side which drew against Brighton, with Anders Lindegaard and Pearson coming into the starting XI.
Lindegaard was fit enough to resume after missing the Brighton game with a stomach bug, while Pearson took over from the injured Alan Browne in midfield.
Pearson saw plenty of the ball in the opening stages as PNE went on the front foot and attacked from the start.
The visitors had an early sight of goal with the first of a number of free-kicks they won in a competitive contest.
Adam Reach won it on the byline, close to the corner flag, Daniel Johnson whipping it left-footed into the six-yard box.
It hit a Forest head in the middle, forcing home goalkeeper De Vries to make a smart reaction save.
Chris O'Grady turned well on the edge of the North End box only to drag his shot across goal and out of play on the far side.
A good spell of pressure saw PNE put Forest under pressure with a succession of attacks but they were unable to find a way through.
Paul Gallagher's free-kick from 25 yards hit the top of the wall and looped over the bar for a corner.
Another free-kick, this time just outside the box, presented North End with an opportunity to test De Vries.
But Gallagher, Pearson and Johnson between them, made a right pig's ear of a training ground-routine and saw Forest easily clear.
It was from yet another free-kick which the hosts broke superbly on Preston to open the scoring on the counter-attack.
Pearson's set piece was blocked on the edge of the box, Forest breaking three against two on a retreating defence.
Ben Osborn took the ball down the left and rolled a low cross over to the far post for Oliveira to side-foot home from close range.
That was a bitter blow to North End who had been on control of the game and could easily have been in front.
They almost snatched a quick equaliser, Calum Woods' low shot from the right side of the box saved by De Vries.
The keeper held the ball and Garner's challenge as he anticipated a rebound earned him a costly booking - it was his 10th yellow card of the campaign, triggering a two-game suspension.
As the interval approached, Reach's curling shot from the edge of the box lacked power and De Vries dived to save comfortably.
Garner and Bailey Wright were replaced at half-time by Hugill and Callum Robinson, North End switching to a 4-3-3.
That saw Hugill in the centre-forward position, Robinson and Reach playing either side of him to provide width.
It was Forest with their tails up at the start of the second half, creating three decent openings.
Chris Cohen's free-kick into the box saw Mendes get in behind by the North End defence but he headed straight at the imposing figure of Lindegaard.
An Osborn cross from the left then caught out PNE's back line, Oliveira working himself into a shooting position but took too long to get his shot away and Lindegaard smothered.
Matt Mills' long ball from the back was then tracked down the right side of the box by Mendes, his first-time volley clearing the bar by a few inches.
North End began to find their feet after the half-time changes, Robinson's low shot from outside the box saved by De Vries.
A corner from Reach delivered deep beyond the far post found Hugill, the substitute header's going straight at the keeper.
Hugill was so unlucky not to equalise five minutes after that chance, Cunningham's cross from the left travelling all the way across the pitch and kept in play by Woods.
Right-back Woods put the ball back into the box with the sweetest of crosses, Hugill meeting it at the back stick with a downward header which looked destined for the net.
But De Vries got down superbly to save one-handed, the keeper also blocking the follow-up from Gallagher.
A last throw of the dice as far as the substitutes was concerned, saw Eoin Doyle replace Gallagher with 13 minutes left.
The visitors continued to put pressure on their hosts, with De Vries once again denying them in the 81st minute.
Pearson got a shot away from 20 yards which the keeper tipped past the post at full stretch.
Forest: De Vries, Lichaj, Mancienne, Mills, Cohen (Jokic 72), Mendes (Vaughan 82), Gardner, Osborn, Tesche, O'Grady, Oliveira (Grant 72). Subs (not used): Wilson, McDonagh, Petravicius, Evimov.
Booked: Mendes 33, Macienne 44, Tesche 66
PNE: Lindegaard, Clarke, Huntington, Wright (Robinson 46), Woods, Pearson, Gallagher (Doyle 76), Johnson, Cunningham, Reach, Garner (Hugill 46). Subs (not used): Vermijl, Welsh, Smith, Kirkland.
Booked: Garner 38, Johnson 56, Huntington 89
Referee: Mark Brown (Hull)
Attendance:16,747 (525 PNE)