United faced last season's table-toppers Preston North End on Saturday morning as they returned to league action down in Lancashire.
And they found themselves two goals to the good inside 20 minutes courtesy of a blistering start, with Nic Bollado and Kai Nugent finding the back of the net.
The hosts were back in it on 36 minutes when an inswinging free kick was diverted into the net by Bollado, and things got harder when Alex Potts was shown a red for a second bookable offence.
Carlisle had one chalked off for offside on the hour, and they defended well despite the one-man disadvantage to see it through for an excellent and hard-earned win.
"I have to give credit to the lads because they dug deep to get the three points," youth boss Mark Birch said. "We got our goals early, and we could have had more.
"Even when we went down to ten men we created chances, and defensively they stuck together as a unit.
"This is a great result off the back of a very, very strong performance."