Carlisle United stay bottom after slumping to defeat against Chesterfield
Carlisle United 0 Chesterfield 2: Carlisle's relegation worries showed no sign of easing as Chesterfield scored in either half to win at Brunton Park.
Dilan Markanday and Will Grigg earned the points for the play-off chasing Spireites against an uninspired and disjointed Blues side.
Carlisle remain bottom of League Two on goals scored and two adrift of safety as rivals Morecambe and Swindon Town both lost.
But the Cumbrians failed to help themselves with a largely abject display in front of 6,586 fans in their last home game before Christmas.
Markanday struck the opener after combining with Grigg to open up United on the home left.
And later Grigg swept home the second after Aaron Hayden's error in the Blues box.
Sub Georgie Kelly had their best chances but blazed the best of them over the bar shortly before Grigg struck the Spireites' clincher, which brought an end to Carlisle's five-game unbeaten run.
It was another afternoon where United's lack of goal threat was painfully exposed, while head coach Mike Williamson's selection changes backfired as Chesterfield won at Brunton Park for the first time in 24 years.
United made four changes to the side that started their previous league game against Crewe Alexandra.
Returning from suspension was defender Jon Mellish, while midfield duo Dylan McGeouch and Josh Vela were recalled along with winger Jordan Jones.
Dropping to the bench were Callum Guy, Ben Barclay and Ben Williams, with Kadeem Harris out of the squad.
Another absentee was keeper Harry Lewis with a broken finger, his place among the subs taken by youth team No1 Thomas Randall rather than United's senior third-choice keeper Jude Smith.
There was again no place in the squad for Luke Armstrong and Taylor Charters, as Harrison Biggins returned to the 18 in place of Jack Ellis.
Chesterfield's side was unchanged from their previous league game, with fit-again Tom Naylor returning to the bench for the Spireites.
United lined up with Burey at left wing-back, and it took time for any serious chances to be created, Jones overhitting a pass when Daniel Adu-Adjei was in a good position, and Sam Lavelle showing good timing to clear early Chesterfield danger.
United's pressing in the visitors' half then caused Cook's side some discomfort, and led to an opportunity for Dominic Sadi who, cutting in from the right, was denied by keeper Max Thompson.
Adu-Adjei then blocked a Thompson clearance but the ball spun wide.
A further Sadi shot then forced the latest in a series of Blues corners but Tyler Burey miskicked his attempted finish.
Chesterfield then regrouped and snatched the opener on 25 minutes.
First, Grigg's hold-up play kept it from Lavelle, and Markanday then ran into space to receive the pass before running at Hayden, checking inside and drilling low beneath Gabe Breeze.
Grigg almost broke through for a second before Vela's foul saw him booked - his fifth of the season with a suspension now due.
United struggled to convince with their remaining first-half efforts, Ryan Colclough having a couple of Chesterfield shots blocked.
The Blues worked a free-kick routine late in the half but it resulted in Burey's shot being blocked, while a Spireites break saw Armando Dobra denied at the near post by Breeze.
Late in the half Vela stole a Ryheem Sheckleford backpass but the angle was too tight to profit, while at the other end Dobra's cross just eluded the sliding Grigg.
It brought an end to a far from convincing first-half display from the Cumbrians, and Williamson made a change at the break, bringing on Kelly for Vela.
The visitors also made a substitution, Jamie Grimes coming on for Lewis Gordon.
After Jones had curled a free-kick just out of Lavelle's reach for Carlisle, Colclough shot into the side-netting as Chesterfield revived a free-kick of their own.
Harrison Neal then replaced Burey for Carlisle, as Harper switched to the left, and a powerful Mellish run opened up a chance for Sadi but the loanee was closed down as he shot.
Guy and Biggins were then introduced just after the hour mark as Carlisle looked for a way back, Guy crossing well from the left as Kelly threw himself at the header but sent it over the bar.
There was then controversy as Kelly broke clean through only for the offside flag to be raised, to a furious reaction from Blues fans and some of Williamson's coaches.
With Mellish now at wing-back, Kelly then had a great chance to level but failed to keep his first-time finish down when set up by Sadi.
United's hopes of a comeback were then dashed as they gifted Chesterfield another.
Dobra ran at Hayden, who seemed to have got in front of the attacker to see off the threat, but he failed to prevent Dobra hooking the ball back across the box where the unmarked Grigg finished clinically past Breeze.
Kelly later had a header blocked in front of the line while United's other attacking efforts brought only frustration, the defeat leaving them stuck on one home win all season - and waiting for their first under Williamson.
United: Breeze, Hayden, Lavelle, Mellish, Harper, Burey (Neal 56), McGeouch (Guy 61), Vela (Kelly 46), Jones (Biggins 61), Sadi, Adu-Adjei. Not used: Randall, Williams, Barclay.
Booked: Vela, Kelly, Hayden.
Chesterfield: Thompson, Gordon (Grimes 46), Sheckleford, Araujo, Williams (Naylor 62), Banks, Mandeville, Dobra (Berry 78), Colclough (Hobson 65), Markanday, Grigg (Drummond 78). Not used: Boot, Horton.
Goals: Markanday 25, Grigg 76.
Booked: Grimes, Banks.
Ref: Scott Simpson.
Crowd: 6,586 (558 Chesterfield fans).