Jon Russell’s second-half header condemned United to defeat at Brunton Park.
Luke Armstrong opened the scoring after rolling low beyond Ben Killip on 10 minutes.
Before the visitors’ skipper Jordan Williams restored parity after arrowing an effort into the top corner of Harry Lewis’ goal on 33 minutes.
Shortly after the interval, Barnsley took the lead for the first time, courtesy of John McAtee.
Jon Russell added a third as we entered the closing quarter-of-an-hour.
Prior to United substitute Dan Butterworth netting a late consolation for Paul Simpson’s side.
The first clear cut chance of the game fell to Jack Diamond after he latched onto a Taylor Charters through ball, but it was ultimately cleared by goalkeeper Killip on the edge of his box.
United broke the deadlock as the clock ticked onto 10 minutes. The ball fell the way of Jack Robinson on the left, who nodded forward towards Luke Armstrong and the striker rolled home from close range.
The visitors almost levelled the contest moments later as Nicky Cadden’s cross was met by Sam Cosgrove, but the attacker’s effort proved to be no threat to Harry Lewis.
Barnsley continued to apply pressure in the minutes which followed and if it wasn’t for a diving header from Harrison Neal, Cosgrove may have found himself one-on-one with Lewis.
Neal almost doubled our lead at the opposite end soon after. Jack Diamond showed great energy to beat his man on the left, before setting the midfielder on the edge of the box, who hammered towards the bottom corner, requiring a strong save from Killip.
On 25 minutes, he would have a go once again from the same area of the pitch, but his effort provided the same result – into the arms of the Barnsley ‘keeper.
One minute later, the ball sat for Cosgrove from 25-yards and the striker hammered well over United’s crossbar.
As we approached the half-hour mark, Charters provided some neat interlinking play in the centre of the park with Jon Mellish, before looking to slip through Diamond, but the pass was too heavy for Carlisle’s attacker and rolled out for a goal kick.
The pair would combine once again on 31 minutes with Mellish looking to drive a low ball into the box for the arriving Armstrong, but the ball skidded past the striker who was unable to get a touch.
One minute later the visitors were level. Midfielder Luca Connell set right-back Jordan Williams outside the area, whose effort flew into the top corner beyond Lewis.
Following the equaliser, Barnsley kept themselves on top, creating a few strong chances and looking most likely to take the lead.
John McAtee set Connell, who lashed towards goal on the volley, but Neal made an important block as we edged closer to half-time.
As the fourth official indicated a minimum of three additional minutes, Cosgrove fired from distance, forcing Lewis to tip the ball over for a corner.
Half-time: Carlisle United 1-1 Barnsley
Two minutes into the second-half the visitors looked certain to take the lead, but Paul Huntington made a terrific last-ditch challenge to turn the ball behind for a corner, which in the end came to nothing.
Barnsley’s strong start after the break would be rewarded moments later. Connell picked out Cosgrove, who squared the ball to McAtee at the far post, who bundled home to give Neill Collins’ side the advantage.
On 53 minutes, the ball arrived at the feet of Mellish, who struck a left-footed shot from distance, but it flew wide of Killip’s goal as the Blues went in search of their second.
Diamond would have the next shot on goal, but his powerful effort landed into the arms of Killip.
Lewis made a strong save in the minutes which followed, denying McAtee a second and Barnsley a third of the night.
Cosgrove hit the post following a ball from the right by O’Keeffe, but the linesman deemed the frontman to be offside on 61 minutes.
On 67 minutes, United were awarded a free-kick, which was delivered by Charters and met by Huntington, who nodded off target.
Robinson sent a low cross into the box for Armstrong as we entered the final 20 minutes, which forced Earl to clear behind for a corner.
Barnsley extended their lead on 76 minutes. O’Keeffe delivered an outstanding ball to the back post, which was glanced into the back of the net by defender Jon Russell.
Aiden Marsh, who was fresh off the bench, almost added a fourth for the visitors inside the final 10 minutes, but his header went just wide of Carlisle’s far post.
On 87 minutes, we had one back. Robinson’s ball down the line found Armstrong, who picked out Butterworth, before the attacker then rounded the ‘keeper and tapped in our second of the evening.
United continued to push as we entered stoppage time, but were unable to breach the Barnsley defence and find a late equaliser.
Full-time: Carlisle United 2-3 Barnsley
Goals
Carlisle United: (Armstrong 10’), (Butterworth 87’)
Barnsley: (Williams 33’), (McAtee 49’), (Russell 76’)
Bookings
Carlisle United: N/A
Barnsley: (O’Keeffe 66’), (Killip 90’), (Grant 90+4’)
Teams
Carlisle United: Lewis, Emmanuel, Lavelle (Barclay 86’), Huntington ©, Mellish, Robinson, McGeouch (Butterworth 81’), Neal, Charters (McCalmont 74’), Diamond (Gibson 81’), Armstrong
Unused subs: Breeze, Armer, Maguire
Barnsley: Killip, Williams ©, Russell, de Gevigney, Cadden, Cosgrove (Marsh 73), O’Keefe, Phillips (Cole 60’), Earl, McAtee (Grant 73’), Connell
Unused subs: Ravenhill, Benson, Cotter, McCart
Match Officials
Referee: Ed Duckworth
Assistant Referee 1: Ivan Stankovic
Assistant Referee 2: Conor Brown
Fourth Official: Ben Wyatt
Attendance: 5522 (813 away)