Manager Simon Grayson felt fundamental mistakes resulted in their downfall this evening.
However, North End made amends for their slow start through Jordan Hugill to equalise mid-way through the first half.
The all yellow Lilywhites frustrated the home side and their supporters for large parts of the first 45 minutes and looked well worthy of at least going in level at the break.
However, a goal on the stroke of half-time from Christian Atsu was ultimately a massive blow to North End's chances with Matt Ritchie and a Perez second secured the hosts' promotion back to the Premier League at the first attempt.
"It's a disappointing night," said the gaffer to PNEPlayerHD after the game. "Basic mistakes have cost us - we started the first five to ten minutes poorly. We expected them to come out because of what was at stake for them but we gave them a free opportunity from a set piece.
"We get back into the game and kept possession and probably should have scored another. We had some good opportunities and limited them to set pieces but then we gave the ball away slopply on the stroke of half-time and it gives them a massive impetus for the second half. Again, in the second half we did the basics wrong and if you do that you're going to be punished by the opposition.
"You could sense the anxiety around the ground; Jordan led the line really well and Tom Barkhuizen was a constant threat down that left hand side. The midfield three was quite dominant and apart from a few set pieces, they didn't create too many opportunities."
The task of overturning the result was made all the more difficult when Paul Gallagher was sent off for handballing on the line, resulting in Ritchie converting the penalty from the spot.
"It felt like ground hog day when we went down to ten men last time," continued Grayson.
"They needed that third goal and when we went down to ten men it was never going to be easy for us. From then on, it was making sure we didn't shift too many goals. Again, all of the goals were preventable from a set piece. They've not had to work hard enough and that's a trait that we've had last month and that's something we need to sort out.
"We knew it was going to be tough and that the crowd was going to be up for it but we needed to be up for that but we made it too easy for then. Huge congratulations to Rafa and his staff for getting promoted and they're very worthy of that and we wish them well for the future.
"We've got to be better, there's no two ways about it - we need to keep the ball better - we showed them too many opportunities. We don't want to finish the season with a whimper because, for 98 percent of the season, apart from the last four games it's been an outstanding effort."