Crawley captain Gary Alexander scored twice to bring Preston's five-game unbeaten run to an end.
Nicky Adams went close for Crawley when he drilled narrowly wide during a quiet first half.
Town took the lead when Alexander headed in Adams' cross, before the striker curled a second past Thorsten Stuckmann from the edge of the box.
Paul Huntington slotted in a late consolation from Joel Byram's free-kick, but Crawley held on to win.
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Preston North End manager Graham Westley told BBC Radio Lancashire:
"It was a different test, against a promoted side who are doing well in their new league. They know how to win games.
"In the level of quality, there was probably little to choose between the two sides.
"In terms of work ethic, I think they showed a little bit more than us.
"We've been used to winning games with a certain level of work and a certain quality of football, but we didn't step our game up today. There's evidence today that we've got work to do."
Crawley Town manager Richie Barker told BBC Sussex:
"I thought we were excellent today. The players attitude is fantastic on a daily basis.
"To come here and win the game and be the better side speaks volumes about the players.
"I've learnt a lot about a few players today. I thought Bulman and Connolly were fantastic.
"If the players believe in themselves, they'll do good."