Shrewsbury pulled away from the dog fight at the foot of Nationwide Division Three when on loan Rotherham defender David Artell grabbed a late winner at Brunton Park.
It was only the Shrews' second away win of the season but the Cumbrians' ninth defeat in ten games.
Despite losing, Carlisle boss Roddy Collins was defiant after the game saying: "I'm not going to lose any sleep over the situation we're in.
"We worked hard and results will turn around for us. Kevin Ratcliffe will be over the moon they've taken the three points.
The visiting boss Kevin Ratcliffe said: "I was disgusted with our performance but delighted that we won. This was the worst we've played all season but we've got the result."
The result was harsh on Carlisle as they were the better team for much of the game.
However, the Cumbrian defence has been gifting goals all season and it was business as usual as Karl Murray was left unmarked to fire Jason van Blerk's cross past Peter Keen after only 37 seconds.
Still reeling, Carlisle almost let the visitors in for a second when keeper Ian Dunbavin's long clearance rebounded off Darren Kelly's back and fell to Nigel Jemson who was unlucky to see his 30-yard effort sail just wide.
Carlisle fought back and on loan Everton youngster Leon Osman crafted space to test Dunbavin with a shot from the edge of the box and then skilfully beat four defenders before testing the keeper.
Ryan Baldacchino hit the side-netting and Craig Farrell appeared to have a fair claim for a penalty but referee Scott Mathieson was deaf to his appeals.
Carlisle kept up the pressure after the break and got the reward their endeavours deserved when Mark Magennis lashed the ball across the six-yard box and it struck Matthew Redmile to finish in the net.
Jemson had a goal disallowed for offside for the visitors but Carlisle still looked the likely winners.
Dunbavin was a rock in the Town net and kept the Shrews in the game until Artell was given a free header to clinch the points from Ian Woan's free kick