The under-18s were at the fantastic Liverpool Academy facility in Kirkby on Thursday afternoon for what became a very entertaining encounter.
Marc Bridge-Wilkinson's young Reds are a team brimming with talent, and they set a good pace and tone to the game which the visiting Blues more than matched for long periods.
The home side created the first opening of the afternoon with a flowing move down the left flank. That brought a shot on the run from a neat reverse pass which rolled to the edge of the box. Barry had it covered as it whipped just over his bar.
Carlisle responded with some determined tackling in the middle of the park and close pressing from Nugent saw him come away with the ball at his feet. He had options left and right but he went for the shot, and the keeper stepped across to make the save.
Both sides battled for space but liverpool were gifted a goal on 18 minutes when hesitiation in defence left men to spare. Highly-rated forward Keyrol Figueroa shouted for the pass and the Honduran under-20 international made no mistake from close range.
Keeper Jacob Barry was called into action when a screamer angled at his bottom corner moments after the restart, and a whipped corner from his fingertip touch somehow made its way across the face of the target unhindered in what was a strong spell for the hosts.
The Cumbrians started to find their passing range and Swinburn, Hill and Bell bounced off each other as they carved a way into the area. Matty Bell almost picked out Carr but his cut back was diverted behind.
Barry pulled off the save of the first half just before the break when a dangerous cross was met on the full by Koumas. It looked a certain goal, but agility from the glovesman saw him block the point-blank thunderbolt before clawing the spinning ball off the line.
United looked up for it at the start of the second period and Swinburn wasn't too far away as he popped one high after the stopper had parried a low drive.
But Lewis Boyd had to be alert at the other end when a downward header ripped his way. He showed good hands to keep the situation under control.
The game became nip and tuck, but the away team deservedly levelled when a rushed clearance was gobbled up by Ryan Carr. He kept his cool before picking his spot.
Mason Hardy had a snapshot saved as United started to look the more likely, but Boyd was called into action when a fast-paced break left him with two attackers to contend with. A parry from a grasscutter left him needing help, and that was provided by Bell, who made a vital intervention.
With Carlisle pushing forward the Reds took advantage of the unexpected room they were given when they overturned possession late in the day. Lewis Koumas - son of former Tranmere favourite Jason - beat the offside trap and calmly rattled it home to restore the lead.
Kai Nugent tried one from 25-yards as the clock ticked down, and Hardy curled another wide as he tried to round off another decent move.
But Lewis Boyd received deserved praise as he completed a fantastic double save to deny the hosts a third goal from the last attack of the game.
United came away from a real test with much to be pleased about, having passed and moved the ball with purpose against a very good Category 1 opponent.
United - Barry (Boyd), Potts, Walsh (Fitzpatrick), Gordon (Walsh), Bell (Fitzpatrick), Allan (Hetherington), Carr, Nugent, Swinburn (Hill), Hardy, Hill (Maddison).
Goal - Carr (52)
Booking - Carr (44)