Preston North End handed out United's biggest defeat of the season as the Cumbrians fell apart in the second half having worked their way back into the game just before the break courtesy of a Gary Madine goal.
A foul on David Amoo brought an early free kick for United and Symington sent it right onto the penalty spot from deep. A half clearance sat up for Thirlwell but his volley was blocked at source.
Another United set piece caused problems when Chris Chantler floated the ball to the far post. Madine's nod down bounced back off a defender and his snapshot hit O'Hanlon on the shin before it bobbled just past the upright.
It was a tight affair and Preston's first chance of the day also came from a deep free kick. It was a wicked delivery and Stuart Beavon applied the touch it needed to guide it into the bottom corner.
The home side looked dangerous and a quick exchange of passes left Laird with a path to goal. He went for the shot and he was disappointed to see it fly over the bar.
The white shirts stayed forward and Symington did well to clear a fizzed cross at the back post before Gallagher could finish it off. The big number 12 stayed forward and he was on hand to pick up the pieces as a low cross from Laird bounced back at his feet. He put his laces through it but Pickford stretched a hand out and beat the effort away.
Carlisle earned brief respite from the home attacks when O'Hanlon nodded a Redmond corner over, but Preston doubled their lead moments later when Holmes wriggled his way through three challenges to go one-on-one with Pickford. The keeper got a hand to his attempted lob but Alan Browne was there to claim his first goal for his club as he poked the ball into an empty net.
It was all Preston and more good play out wide put Kilkenny into a dangerous area. He picked out Gallagher but his first time volley arced off into the stands.
United's first shot on target came on the half hour when Redmond picked out Madine with a low pass. Clarke stopped the first shot and Rudd was there to grab the header as the striker tried to apply enough power to find the top corner.
Carlisle enjoyed a better spell and a lobbed ball into the area had Madine interested again. Rudd flapped at it and Keane gratefully hooked it away as Potts steamed in to make a touch.
And United got the reward their much better period of play deserved when Redmond clipped another teasing corner into the penalty area. Madine rose highest to thunder a header past Rudd and he was delighted to see it hit the roof of the net as it bounced up off Keith Keane's shoulder.
The balance of power had switched and Madine beat Rudd to another high cross to leave O'Hanlon with a chance to shoot. Keane was there once more to make a timely intervention. A low cross from Amoo then caused all kinds of problems as first Redmond, and then Robson, tried to round the move off. A combination of good defending and bad Carlisle luck meant the home one goal advantage was preserved.
But it was Carlisle who were left to breathe a sigh of relief deep into time added on for the half. Kilkenny did the leg work as he wriggled his way to the byline and O'Hanlon stuck out a leg to send Gallagher's shot wide as he set himself to celebrate.
Preston had their two goal cushion restored within two minutes of the second half restart when seemingly harmless cross from Davies caught Pickford in two minds. His fumble left Gallagher with an open goal to aim at but he kept his composure and fed the ball into the path of Lee Holmes. The angle was tight but he made no mistake as he slid it through Brown's legs and into the waiting net.
The Whites started to enjoy their football and their fourth came from a passing move which carved a clean path down the left flank. Craig Davies called for the pass as it came into the box and he put it away at the second attempt following a good initial save from Jordan Pickford.
Gallagher and Beavon weaved a path to goal as United looked shell-shocked and it was a touch from Pickford which took it away from Holmes as he raced in. Tom Clarke then sent a header over from close range and Craig Davies back heeled a low corner wide as the home side turned the screw.
The afternoon went from bad to worse as Kilkenny was allowed to go on another run into the United box. He had players queuing up and Craig Davies was the lucky recipient of a goal on a plate as he arrived late to take it in his stride. Pickford saved the first effort but he could do nothing about the follow up which bounced over the line off the striker's knee.
Preston were, by now, brimming with confidence and Gallagher had a wonderful volley palmed away as the policy became 'shoot on sight.' Craig Davies heaped the misery on for the travelling blue army when he adjusted his body to tap a deflected Brownhill shot from the angle into another open goal.
Carlisle heads had dropped and Preston and Gallagher tested Pickford with another series of firm strikes which had to be parried away. But salt was rubbed into the gaping wound when Craig Davies tussled with O’Hanlon for a ball over the top. He broke clear to register his hat-trick in emphatic style with an accurate finish past the stranded stopper.
Preston kept going, with chances for Kevin Davies and Paul Gallagher going close, and it was with some amount of relief that the blue shirts greeted the final whistle.
Preston - Beavon (10), Browne (20), Holmes (47), Davies (56, 78, 82)
United - Madine (41)
Preston - King (60), C Davies (82)
Preston North End - Rudd, Keane, Laird, Clarke (Huntington 83), Beavon (K Davies 74), Holmes, Gallagher, C Davies, King, Browne, Kilkenny (Brownhill 74). Subs - Stuckmann, Wright, Buchanan.
Carlisle United - Pickford, Symington, Chimbonda (Robson 39), O'Hanlon, Brown, Chantler, Thirlwell, Potts (Noble 61), Redmond (Miller 71), Amoo, Madine. Subs - Fleming, Byrne, Guy, Meppen-Walter.
Referee - Mr Mark Haywood
Attendance - 11,428 (1,374 away fans)