Carlton Morris' 12th goal of the season with just over quarter-of-an-hour to go looked to have given the fourth-placed Hatters victory at Deepdale.
But Troy Parrott netted an 81st-minute penalty, after the North End striker's cross struck Tom Lockyer's outstretched hand, to rescue a point for the hosts who had played the final 40 minutes with ten men after Ben Whiteman was shown a straight red for a foul on Pelly-Ruddock Mpanzu.
Manager Rob Edwards made one change from the side that drew 1-1 at Coventry, with Alfie Doughty missing out through an injury he sustained at the weekend, and being replaced by Fred Onyedinma who was making only his second start since October.
Dan Potts was on the bench after missing the last few matches, while striker Joe Taylor - who made his Luton Town debut on Saturday - was named amongst the substitutes once again, alongside Luke Berry who scored a brace against this evening's opponents in March last year.
Preston made most of the early running in a scrappy opening period, but Elijah Adebayo headed wide from a Jordan Clark corner as the Hatters found their feet.
In the 21st minute they were denied three times, Adebayo's shot saved at his near post by keeper Freddie Woodman, with Clark seeing a follow-up shot blocked and then a second effort deflected over the bar by the head of Alvaro Fernandez, who had backpedalled to almost on the goal-line.
Home fans started to get restless as Morris climbed highest to head another corner goalward, before Adebayo pressed Woodman in his area, with the former Newcastle keeper grateful to gather the loose ball with his clearance half-blocked by the Town striker.
Adebayo spurned a glorious chance to open the scoring in the 33rd minute, dragging his shot wide after taking Osho's diagonal pass on his chest and evading the attention of his marker Andrew Hughes, with just Woodman to beat.
Amari'i Bell was next to see a chance go begging as a wonderful passing move from Osho in the left-back area to right-wing, via Mpanzu, Burke and Clark, saw Onyedinma sprint to the byline and cut the ball back for the left wing-back to sidefoot a right-footed effort just wide.
Town were completely dominant by this point, with the ball worked out to the right angle of the box once more, again by Osho and Clark, but Morris' shot was blocked as he looked to work space in the area.
The hosts were reduced to ten men five minutes into the second half as Ben Whiteman was shown a straight red card for a late challenge on Mpanzu.
By the 54th minute the Hatters should have had a goal advantage as well as the extra man, Clark playing Adebayo through the middle, but the striker's shot drifted agonisingly wide of the far post after he opened his body up to sidefoot the ball right-footed.
Preston reminded the Hatters that they could still carry a threat with Troy Parrott firing into the side-netting, but Town came as close as possible to opening the scoring on 67 minutes when Morris headed another Clark corner against the bar.
Adebayo headed over from inside the six-yard box, then Lockyer flicked another corner on - but no-one could get on the end of it - as Clark delivered a host of dangerous set pieces into the near post area.
The breakthrough finally came in the 73rd minute, and it was no less than the Hatters deserved as Bell beat his man brilliantly and crossed from the left, a slight deflection looping the ball to the far post where Morris was ready to head home.
Preston were handed a route back into it in the 81st minute when Lockyer was penalised for handball as Parrot volleyed in a cross at point-blank range, with the home forward rifling home the spot-kick.
It was completely against the run of play, with the Hatters in complete control to that point.
But that was all Town could bring home as Preston managed the closing stages well, even denying Clark with a close-range header in the fourth minute of additional time before Woodman saved a Cauley Woodrow effort comfortably, to bring their five-game home losing streak to an end.
Goals:
Preston North End - Parrott (81' pen)
Luton Town - Morris (73')
Att: 13,903 (457 Hatters)