Matt Taylor's Saddlers headed up to Cumbria in a buoyant mood following their brilliant triumph at Port Vale in midweek.
But this represented a huge comedown, with the hosts ending a 12-match winless run.
Taylor's lot did not spark into life on a chilly afternoon and were made to pay as substitute Tristan Abrahams caught them cold after a set piece in the 88th minute.
Walsall's search for back-to-back successes in the league this campaign goes on.
If they wish to be anything more than a mid-table outfit this term, that simply has to change.
The Saddlers were too often guilty of launching the ball upfield, looking for George Miller, rather than playing through the thirds with purpose. They just switched off for Abrahams' winner, too.
As soon as they threaten to really build momentum, they come up short.
Carlisle are the latest in a growing line of down-the-bottom teams Walsall have given a leg-up.
The Saddlers have potential and there is no need for panic stations, but they are going around in circles.
Walsall were forced into a change from the victory at Vale.
Brendan Kiernan – who came up with the winner in that game – did not travel to Cumbria due to a foot injury.
Otis Khan came in at left wing as a result, at a freezing Brunton Park.
The 293 Saddlers fans who were brave enough to make the long journey up north had to contend with the effects of Storm Arwen, with the railways especially chaotic.
Making it to the game was an achievement in itself. Still, the Walsall faithful were hoping for a bright display.
Taylor was celebrating his 40th birthday and wanted to mark it in style as well.
The Saddlers went close with a couple of early efforts. Conor Wilkinson, looking for his first away goal for the club, went on a driving run in the opening minute.
He was eventually stopped, but the ball fell kindly to Khan, whose curling shot flew inches past the far post.
Wilkinson then had a powerful left-footed strike sting the palms of Carlisle keeper Mark Howard.
On the whole, though, the pace of play was not the greatest.
The bobbly surface was not really one for silky passing moves and, at times, Walsall gave the lowly hosts some hope with a few loose balls.
Thankfully, Keith Millen's lot – who gave 18-year-old striker Sam Fishburn his first league start – were not sharp enough to punish those defensive lapses.
They were having the lion's share of possession, but they were not doing much with it.
The longer the Saddlers went without forcing the issue, though, the more Carlisle grew in confidence.
After a mistake by Stephen Ward, Joe Riley spotted Carl Rushworth off his line and sent an audacious attempt from 40 yards just over.
Jordan Gibson nearly opened the scoring, too, as his clever side-footed shot went through a crowd of bodies and kissed the post on its way out.
That was all for the first half, which was a poor watch.
Walsall had lacked any proper quality with the ball while the home side, it must be said, looked every bit a team in 23rd.
The Saddlers continued to look lethargic after the break.
Jack Earing had the opportunity to pick out the run of Khan, but instead opted for centre forward Miller and overcooked the pass.
That summed up the performance from Taylor's lot, and the Walsall chief had seen enough, making his first switch shortly after the hour as Kieran Phillips replaced Khan.
Chances remained at a premium for the Saddlers, though.
Miller had a half-volley swatted away by Howard while Joss Labadie saw a long-range shot spilled, but this looked all set to end a goalless draw, with Carlisle offering very little.
Emmanuel Osadebe threatened to grab a winner for Walsall as his 25-yard fizzer sailed narrowly off target.
Instead, though, it was the hosts who bagged themselves a much-welcome three points late on.
The Saddlers were caught napping as a free-kick was floated to the far post and then clipped back across goal, where substitute Abrahams was left with a simple tap-in.
Carlisle's first victory in 13 attempts and the stop-start nature of Walsall's season continues.
Carlisle (4-4-2): Howard; Mellor, Feeney, McDonald, Armer; Riley (Charters, 37), Whelan, Guy (c), Gibson; Fishburn (Mampala, 85), Young (Abrahams, 63)
Subs not used: Simons (gk), Devine, Dinzeyi, Clough
Goal: Abrahams (88)
Walsall (4-2-3-1): Rushworth; White, Menayese, Monthe, Ward; Labadie (c), Earing; Wilkinson, Osadebe, Khan (Phillips, 65); Miller
Subs not used: Rose (gk), Taylor, Leak, Perry, Kinsella, Shade
Attendance: 3,795 (293 Walsall fans)
Referee: Scott Oldham