Goals in either half from Byron Moore and Brad Inman sealed a much-needed win for Crewe, who had lost their last three in all competitions, conceding 11 goals in the process.
Crewe's fortunes appear to be heading with them up the Sky Bet League One table, but Simon Grayson's Preston have now lost three on the bounce.
Preston remain fifth, while Crewe are out of the bottom four and up to 17th, but boss Davis insists no one at the club will be crowing with one win in seven.
"It can only help our confidence, but we've only made one little step forward - that's all. We certainly won't get carried away and I won't let that happen," said Davis.
"We've got to build on this. It's important to gather some momentum as we have in previous years. We've always worked well off a good result and hopefully we can push on and get some more.
"It's three points and a victory and it eases us away from the bottom four, which is important. If we can keep this level of performance up and keep it nice and tight like we did, we'll be alright.
"We worked really hard for the win. Some of the performances over the last two or three weeks have actually been decent, but the results weren't - they were awful with the mistakes we made.
"But the actual performance as a team has been decent and that's what I've tried to pick up and build on over the last few weeks - that's the only way we can build confidence."
Preston could have gone ahead after two minutes, but Scott Laird's curling effort was well saved by Steve Phillips with Iain Hume firing an effort onto the crossbar from the resulting corner.
Stuart Beavon then drew another save from Phillips before Moore tucked home Chuks Aneke's clever chipped through-ball against the run of play in the 27th minute to give Crewe the lead.
Kevin Davies headed a Hume cross agonisingly wide just before the hour-mark before Crewe went up the other end to score, Inman curling home from outside the area in the 64th minute.
Crewe almost had a third as Adam Dugdale hit the crossbar soon after, but boss Davis admitted they were fortunate not to find themselves behind early on such was Preston's dominance.
"It was a crazy game. We worked hard as a team and we've had that little bit of luck in the first few minutes where they've hit the bar," Davis added.
"We've then gone and scored and got control of the game, which we haven't been able to do much this season.
"We took a bit of time to settle into the formation, but we put a lot of bodies behind the ball and hit them on the counter.
"We managed to stifle them and keep a high line to keep Davies out of the box. We could have kept possession a bit better, but inviting them on to us and catching them out was a good play."