It was a game of contrasting halves, PNE dominating the first 45 minutes and should have had more to show for their efforts than Simon Makienok's close-range finish on the stroke of half-time.
Forest bossed the second half, denied by two great saves from Chris Maxwell before the North End keeper inadvertently put through his own goal - a shot from Thomas Lam hitting the post and striking him on the heel.
Greg Cunningham and Alex Baptiste both cleared off the line in the closing stages to keep the scoreline level, although the visitors had late chances themselves through Jordan Hugill and Alan Browne.
The loss of Ben Pearson to injury early in the second period certainly affected Preston, with the home side getting more of a grip on midfield in his absence.
The North End side had shown one change from the team which beat Blackburn last Saturday, Browne replacing Hugill.
They matched Forest's 3-5-2 system, Browne joining Daniel Johnson and Pearson in midfield, with Baptiste, Tom Clarke and Bailey Wright the three central defenders - Marnick Vermijl and Cunningham in the wing-back roles.
PNE were lively from the start, just a minute played when Vermijl's deflected shot fell into the path of Callum Robinson behind the Forest defence, goalkeeper Vladimir Stojkovic spreading himself well to block Robinson's shot.
Stojkovic was forced into action again, saving Browne's low shot at the near post with his feet, the rebound fired across goal and wide by Robinson.
Browne was proving to be the visitors' action man, getting in advanced positions a number of times as North End pressed their hosts to good effect.
A surging run from the back saw Baptiste exchange passes with Makienok before sending a low shot from the edge of the box just wide of the far post.
The woodwork denied Preston the lead in the 13th minute, Browne's shot from 20 yards coming back off the bar with Stojkovic perhaps having got the faintest of - but important- touches to the effort.
Forest seemed determined to play out from the back at every attempt, Makienok and Robinson pressing well to limit the effectiveness.
That said, the home side did have their moments in the first half, David Vaughan's powerful shot from an acute angle on the left side of the box forcing Chris Maxwell into a diving save at the near post.
Their best chance was volleyed over the bar from six yards by Nicklas Bendtner two minutes before the interval, that a costly miss with North End finding the net at the other end just as the clock ticked into the 45th minute.
Johnson took possession 25 yards out and sent a left-foot cross into the box towards the back post.
Cunningham ran to meet it, cushioning a header back across goal to present Makienok with a simple finish from inside the six-yard box.
North End lost Pearson in the 51st minute after he came off second best in a challenge with Forest substitute Armand Traore, the midfielder tried to run it off but clearly was in a lot of pain.
While they were getting Ben Pringle ready to replace him, Forest broke forward against the 10 men, Ben Osborn's pass finding Matty Cash in the box, his shot pushed behind by Maxwell at the near post.
Maxwell produced a fine save with an hour played, diving low to his left to get a glove to Cash's volley after Traore's cross from the left had found him in the middle.
Shortly after, the keeper was at it again, getting fingertips to Bendtner's curling shot to divert it beyond the far post, the Forest front man having escaped the attentions of Baptiste to get beyond the North End defence.
After making the two saves, Maxwell was so unfortunate to be credited with the own goal which brought Forest's equaliser in the 68th minute.
Eric Lichaj got down the right channel, his low cross met first time by Lam whose shot hit the base of the post and bounced back against Maxwell's heel and into the net.
Forest were dominant at that stage, it needing a clearance off the line by Cunningham to keep out Apostolos Vellios's header.
Preston found their attacking legs again as the game entered the last 10 minutes.
Johnson dropped a ball over the top of the home defence which substitute Jordan Hugill met and headed just wide.
Browne's shot from just inside the box was then parried by Stojkovic, the keeper smothering Makienok's follow-up.
Another clearance off the line, with the aid of the woodwork, kept North End on level pegging in the 84th minute.
Vellios' flicked header went over Maxwell and bounced goalwards, Baptiste racing back and heading the ball up against the underside of the bar.
Forest: Stojkovic, Perquis (Traore 46), Mills, Worrall, Pereira, Cash, Lam (Kasami 74), Vaughan, Lichaj, Osborn, Bendtner (Vellios 66). Subs (not used): Mancienne, Carayol, Grant, Henderson.
PNE: Maxwell, Baptiste, Clarke, Wright, Vermijl (Huntington 88), Pearson (Pringle 51), Browne, Johnson, Cunningham, Robinson (Hugill 78), Makienok. Subs (not used): McGeady, Grimshaw, Spurr, Lindegaard.
Referee: Tony Harrington (Cleveland)
Attendance: 15,864 (709 PNE)