United, without a win at home in 13 games, were up against a Millwall side pushing for promotion.
On paper the Lions should have torn the home side apart but football doesn't work like that.
It was a glorious day at Brunton Park and Graham Kavanagh's opening goal after just seven minutes was one to savour.
Lurking 30 yards out, the former Republic of Ireland international lashed home an unstoppable drive right into the top corner to calm the nerves of even the most ardent of United fans.
The 35-year old was immense from start to finish and was at the heart of everything positive Carlisle did.
In fact from front to back the United team looked confident and played with passion and commitment.
Striker Joe Anyinsah had a great chance to double the lead when he latched on to a long throughball. Unfortunately it took an age for the ball to drop giving Tony Craig time to get back and clear the danger.
Cleveland Taylor then had his shot saved by David Forde, the winger's curling volley bringing a full-length stop from the Lions shot-stopper.
Millwall had chances of their own but veteran striker Neil Harris blazed over the bar from ten yards.
United found the net again five minutes after the re-start. Taylor's cross was only half-cleared and captain Paul Thirlwell curled home a brilliant shot from 20 yards.
Millwall showed they were still in the game when Gary Alexander headed against the bar and Nadjim Abdou should have halved the deficit with three minutes left but he failed to hit the target from 12 yards.
The fourth official signalled five minutes stoppage time but that didn't stop the Blue Army from belting out "The Blues Are Staying Up".
As the final whistle went a mass pitch invasion followed with the Great Escape blaring out over the PA.