Peter Whittingham set them on their way a minute before the interval and two more from Michael Chopra, one of them a penalty, and a debut goal from Roger Johnson, all in the second half, saw the Bluebirds comfortably home.
Not even a disputed penalty for the visitors could dampen home spirits.
There was a shock in the Bluebirds starting line-up with David Forde making his debut in goal in place of the unwell Neil Alexander.
David Nugent showed why he is so highly rated in the early stages and he could have opened the scoring in the 19th minute with a first-time shot, but Forde got across to palm the ball away.
Chopra hit a free-kick that was tipped over by Andy Lonergan in the visitors' goal and then Steven Thompson glanced a header wide.
The Bluebirds took a deserved lead in the 44th minute when a Paul Parry cross was helped on by Chopra and Whittingham lashed a right-footer beyond the diving keeper.
The second half opened in explosive style with three goals in the three hectic minutes.
Chopra was brought down by Liam Chilvers in the 51st minute and he promptly despatched the spot-kick for his 20th goal of the season.
Two minutes later Preston clawed themselves back into the game when skipper Graham Alexander converted from the spot after Johnson had nudged Neil Mellor in the penalty area.
Straight from the kick-off, Cardiff restored their two-goal advantage when Johnson arrived at the far post to head in from a tight angle.
It was all Bluebirds now and they extended their lead in the 66th minute when the impressive Whittingham put one on a plate for Chopra.
The game was as good as over, but still City pressed forward in waves with Whittingham and Parry causing havoc down the flanks, while Thompson intelligently linked up play through the middle.
Paul Simpson brought on Patrick Agyemang and Mellor upfront, but Glenn Loovens and Johnson were more than equal to the task and City fully deserved their victory.