Promotion-chasing Huddersfield Town suffered their first defeat in nine games as Carlisle's Lee Miller grabbed a dramatic winner in injury-time.
Ex-Terriers midfielder James Berrett put the hosts in front when he finished off a passing move by calmly slotting home from eight yards out.
Lee Novak equalised when he steered in Alan Lee's low cross, before Lee saw his shot rebound off of the post.
That proved costly as Miller headed in from six yards for the winning goal.
VIEWS FROM THE DRESSING ROOM
Carlisle United manager Greg Abbott told BBC Radio Cumbria:
"We are worn out. Everyone is on their knees in that dressing room with elation.
"The amount of effort and energy I think everybody has put into the day - to send home a really big crowd happy.
"They've worked so hard. You compare the two squads and we are up against it.
"What you've seen is a fantastic performance from a group of players who deserve to be up there."