The under-18s were back at home on Tuesday afternoon as they played host to Preston North End.
And it was a comfortbale victory off the back of a controlled display as they took their chances and defended resolutely.
Having said that, it was the visitors who came out of the blocks the fastest, and they turned possession over with just two minutes on the clock, deep inside the home half. Young stopper Gabriel Breeze was off his line smartly to make an important block.
The hosts gave themselves a shake and they started to dominate the territory, with willing runners left and right. Walton was an example of that when he burst through a challenge before cutting the ball back. It was just behind Leslie and the moment was gone.
More good pressure brought a free kick when Walton was felled, and Rooks sent his delivery at the back stick. Barnett got there but his glancing touch took it wide.
There was more work for Breeze to do at the other end when the white shirts worked space on the left flank. Breeze launched himself at the shot to touch it past the upright.
Wide man Lewis Rooks was lively throughout the first half and he beat two before picking out Bell. His fellow winger brought it under control before a rasping volley was unleashed. The away keepr made a strong save.
Home pressure started to mount and Fishburn was disappointed to send a header from a Watt cross beyond the target.
And both Leslie and Walton had efforts charged down at source as the stubborn Preston back line refused to wilt.
There was a reminder that concentration was needed when North End won a corner just before the break. It was cleared, but the second ball was immediately whipped back into the box. A firm header had to be beaten away by the alert Breeze.
United got the lead their first half display had deserved when left back Max Kilsby suddenly found himself as the most advanced player on the pitch, after he had supported a forward move. It came his way and he settled it down with a neat first touch before leaving the keeper with no chance with a stunning finish.
The home advantage was doubled just two minutes into the second period when Fishburn showed great poise to take a through ball with his instep. Power and pace followed as he shrugged off the defensive attentions and his finish was crisp and cool.
Carlisle governed the pace of the game, without creating too many clear-cut chances, but they were close again when a huge kick from Breeze found Fishburn with his back to goal. He shot on the spin but he'd lost his bearings and he angled it wide.
United's win was wrapped up with five minutes left to play when Rooks caused confusion with a measured ball over the top. A weak connection from the defender allowed Fishburn to pounce, and he doubled his tally for the day when he guided his toe poke into the bottom corner.
Garvey headed at the stopper as the young Blues attacked at will through the closing stages, and the overall performance put to bed the disappointing result at Rochdale on Saturday with the team bouncing back in the best possible way.
United - Breeze, Ellis, Day (Garvey 64), Barnett, Kilsby, Leslie, Walton, Rooks, Swailes (Watt 28 (Taylor 70)), Bell, Fishburn. Subs - Robinson, Simons.
Goals - Kilsby (40), Fishburn (47, 85)