Two killer goals cost United dear as away specialists Luton Town added another notch to the travelling tally with a disciplined win at Brunton Park.
Carlisle pinged the ball around in the opening exchanges and a ball from Joyce to Grainger invited him to cross on the volley. That was initially blocked but Kennedy tackled with strength and he was able to find Stacey on the overlap. It opened up for the shot but his attempted curler was too close to the keeper.
More good work on the right flank put Comley into a good area and he crossed deep to find Kennedy. A touch set Gillesphey for a snapshot but he couldn't keep his rasping drive down.
It was all about the home side and a scuffed clearance from an Atkinson delivery bounced up in front of Joyce. He let fly on the turn but Rea moved across to make a block.
Luton came into it with back-to-back corners on the quarter hour and they almost nicked the lead when a headed clearance popped up in front of O'Donnell. He showed great technique to get his boot round the ball and Gillespie had to dive high to tip the effort over the bar.
Wide man Alex Gilliead used quick feet to create space at the other end but he was rushed and his piledriver blazed over the target.
A quickfire break was the undoing of the Cumbrians midway through the half when Mpanzu burst into the box. His inside pass was picked up by Pigott and he did well as he took a touch and spun on the spot. His low shot left Gillespie with no chance as it went through legs and into his bottom corner.
The visitors defended well but they were opened up just before the break when Gilliead slid a lovely ball through. McQueen whisked it across the face of goal but there was nobody there to finish it off. The blue shirts kept the pressure on but Gillesphey came under pressure and another snapshot was easy for Justham to grasp.
Gillesphey had the ball nicked off his toe as he tried to get on the end of a wicked Grainger corner and Luton made use of the space when Lawless fed Mpanzu from the centre circle. He had just one thing in mind and he was less than a whisker away as his shot on the run shaved the outside of the upright.
The half ended with a fierce shot from Stacey which angled a yard wide and there was work to do as the Hatters took their lead down the tunnel.
Substitute Jabo Ibehre sparked a good attack from the restart when he shielded the ball on the left. Stacey took over with a cross but it was just too high for Gilliead.
Ibehre was involved again when he won a corner for his team and United went close as Wyke threw himself at the ball. He came under pressure and his header ballooned high.
The promise of a fightback was dealt a blow when a ricochet on the edge of the Carlisle area left Pigott with room to cross. Another lucky bounce left McQuoid with time to sweep the loose ball into the back of the net.
Carlisle thought they'd got themselves right back into it when McQueen clipped a cross into Kennedy's path. His instinctive touch was perfect for Ibehre but it was disappointment all round as a toe poke took the ball wide of the mark.
Heads didn't drop and United bagged a goal with their next attack when Ibehre held off challenges to bring Stacey into play. He took his time but it was worth the wait as he thrashed a beauty past the dive of the stopper.
It became attack against defence as Carlisle sent men forward through the closing stages but the disciplined visitors held a strong back line as they kept things at bay.
An overhead kick from Ibehre summed up the frustration when it looped over the bar and there were loud claims that the ball had dropped over the line when Ibehre won a header from a McQueen cross. The keeper was beaten but the officials deemed the clearance had been made just in time.
United - Stacey (61)
Luton - Pigott (23), McQuoid (51)
Luton - McQuoid (74)
Carlisle United - Gillespie, McQueen, Atkinson (Archibald-Henville 68), Gillesphey, Grainger (Asamoah 83), Joyce, Comley (Ibehre 46), Kennedy, Stacey, Gilliead, Wyke. Subs - Hanford, Brough, Sweeney, Thompson.
Luton Town - Justham, O'Donnell, Potts, Rea, Lawless, Green (McGeehan 69), Mpanzu (Howells 85), Lee, McQuoid (Marriott 90), Sheehan, Pigott. Subs - King, Benson, Banton, Musonda.
Referee - Mr Mark Haywood
Attendance - 3,497 (235)