A stunning Jon Mellish hat-trick helped United to a valuable three points away at promotion-chasing Peterborough.
A first half header was added to by a duo of volleys as the Blues claimed a deserved away triumph - despite Harrison Burrows' consolation goal.
Paul Simpson named an unchanged side from that which drew with Stevenage last weekend, while January signing Georgie Kelly was named on the bench for the first time.
It was the hosts who started on the front foot as they dominated possession, albeit without really testing Harry Lewis.
Malik Mothersille had the first opening of the afternoon as he fired over from the edge of the box and Sam Lavelle then had to slide in and block a shot from Kwame Poku after the winger weaved his way into the area.
Mothersille again threstened as he flashed a header wide of the near post for the Posh who couldn't translate their early possession into the opener.
United were then forced into an early change as Jordan Gibson replaced the injured Taylor Charters, and the winger was straight into the action as he provided the assist for the opening goal of the afternoon.
A short corner from Dylan McGeouch allowed the winger to cut into some space, and his dinked cross was powered home from six yards by the head of Mellish.
Peterborough were keen to respond immediately and Ephron Mason-Clark delivered a warning shot as he cut in from the left flank and drilled narrowly over.
Poku then fired wide at the far post as half-time approached, but United headed into the interval with stopper Lewis relatively untested.
And having weathered that pressure at the end of the first period, the Cumbrians doubled their lead just four minutes after the restart.
Luke Armstrong did well to hold up the ball before Mellish took up responsibility - driving into the box and seeing his first attempt blocked before reacting quickly to volley into the roof of the net for his and Carlisle's second of the afternoon.
Posh boss Darren Ferguson responded with a trio of attack-minded changes, but it was still United having the better of the chances - with Gibson seeing a shot deflect agonisingly wide of the post after a sustained spell of pressure.
And the visitors wouldn't have to wait long for a third. Peterborough couldn't fully clear their lines from the resultant corner and after a spell of head tennis, Mellish was on hand to wrap his foot around the ball and send a sumptuous volley into the top corner from 18 yards.
The Posh reduced the deficit minutes later though, as Burrows drilled into the bottom corner from the edge of the box after a cross was cleared into his path.
That buoyed the hosts who laid siege on the United goal. Substitute Jonson Clarke-Harris headed narrowly wide at the back post while Lewis had to get down well to deny Mason-Clark from close range.
But while Peterborough piled bodies forward, an opportunity presented itself for the Blues on the break. After Harrison Neal broke and fed Gibson, the winger rounded stopper Jed Steer before being brought down as he looked to shoot - referee Will Finnie waving away penalty appeals.
The Blues continued to keep the promotion-chasing Posh at bay as the game ticked into injury time, while debutant Kelly - introduced as a second half substitute - came to close to a fourth after trying to chip Steer from range.
But Peterborough kept on knocking and came within inches of cutting the arrears further when Clarke-Harris hooked a volley off the crossbar, with United crowding out David Ajiboye before he could fire home the rebound.
Seven minutes of injury time could have proved a daunting prospect, but United managed it well - even coming close to a fourth when Armstrong poked Gibson's low cross into the arms of Steer.
Three would be enough for the Blues though, who claimed a well-deserved triumph on the road to kick-off the Easter weekend.
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Goals
Peterborough United - Burrows (62)
Carlisle United - Mellish (27, 49, 59)
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Bookings
Carlisle United - Ellis (7), Mellish (33)
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Teams
Peterborough United - Steer, Katongo (Ajiobye 52), Burrows, Edwards, Knight, De Havilland (Clarke-Harris 52), Mason-Clark, Poku (Olakigbe 79), Randall (Fernandez 72), Mothersille (Jones 52), Collins. Subs: Bilokapic, Crichlow
Carlisle United - Lewis, Armer, Lavelle, Butterworth (McCalmont 65), Charters (Gibson 23), Ellis (Emmanuel 78), McGeouch (Kelly 78), Mellish, Barclay, Neal, Armstrong. Subs: Breeze, Diamond, Grehan
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Match officials
Referee - Will Finnie
Assistant Referee 1 - Michael Webb
Assistant Referee 2 - Jonathon Block
Fourth Official - Stephen Finch
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Attendance – TBC
