A second trip to the north-east of the summer saw United face Middlesbrough in their penultimate pre-season friendly fixture.
And a strong performance helped them to take a 3-2 victory in a game where they had to battle back after going behind in the first half.
Trailing by the solitary goal heading into the break, DJ Taylor struck early in the second period to level things up.
Sam Fishburn then put the Blues ahead for the first time on the day before Boro pegged it back to 2-2 in what was a high tempo encounter.
Carlisle rallied and Dylan Garvey found the net late in the day to secure the away win.
Under-18s boss Mark Birch said: "It was a really good performance from everybody.
"The lads worked hard and they ended up with a good win against a very good side."
