It was a comprehensive win for the Under 18s as Max Woltman and Mateusz Musialowski both bagged braces as Jarell Quansah and Kaide Gordon grabbed the other goals.
Liverpool dominated throughout the game, allowing the travelling Teessiders to register just two clearcut opportunities.
With the first team hosting Newcastle just six miles away at Anfield, the spotlight was on the first team, as the seniors failed to make chances pay, a second-half rout from Marc Bridge-Wilkinson's men saw them move into second, two points behind leaders Manchester United.
It was business as usual for the 18's as they started off on the front foot and could've easily had the game put to bet within the first 45 minutes.
James Norris, a standout performer on the day, enjoyed combining with fellow left-sided player Melkamu Frauendorf. The duo combined within the opening quarter and spotted a weakness in Boro's five-man defence. Norris and the German linked up but the former-Hoffenheim trainee rattled the underside of the bar.
It was one-way traffic in Kirkby with the visitors withstanding a barrage of attacks from the hosts. Captain Quansah, came close after he met Musialowski's tempting corner but failed to keep his header down. The skipper made no mistakes minutes later as he ghosted in between the blue of Middlesborough and nodded home into the far corner.
The Reds youngsters have a great opportunity in just six days time as they host Arsenal in the FA Youth Cup at Anfield in the quarter-final. Their first-half showing had scary similarities to Jurgen Klopp's men as they failed to capitalise on their one-goal lead.
Craig Liddle's side were holding on for their lives in the opening half with his side forced to dive in front of the oncoming onslaught to maintain a one-goal deficit.
Woltman spearheaded a Liverpool break, his weaving run had the Middlesborough defenders at sixes and sevens as he cut inside and out, he came agonisingly close with his clever near-post effort only to be denied by the woodwork.
The U18s head coach was slightly disappointed that his side couldn't make their chances pay, he said "It's a tough one because we had some great opportunities and we obviously couldn't take them.
"On a different day, we maybe would've had two, three goals but yeah, it was disappointing we didn't take them but it was really pleasing that we created them in the first place."
The title-chasing youngsters didn't show any sign of letting up in the second 45 and it only took the youngsters four minutes after the restart to add to their lead through January signing Kaide Gordon.
Liverpool's number three, Morris, found more joy on the left-side, he clipped a delightful cross into the danger area and the 5ft 10in Gordon rose highest to head home, following the full-backs over-lapping one-two with Frauendorf.
On the goal, Bridge-Wilkinson said: "It's the first time we've seen him score a header in a game but in training, we've seen him do it. I think Kaide's got lots of potential and he's someone we're looking forward to working with."
Two became three shortly after, Frauendorf was brought down in the box following a wild swipe from Jack Stott. Woltman stepped up and sent Max Metcalfe the wrong way.
The promising Pole, Musialowski, got in on the act shortly after the hour mark before rounding off the scoring late on. The 17-year-old came into life in the second half and showed glimpses of what has many fans anticipating great things. He was on the receiving end of a late tackle from the visitors which brought a rye smile.
Gordon found the youngster, who took a touch on his left and placed his left-footed effort brilliantly in the bottom corner. He completed the scoring with a moment of brilliance, a fizzing pass into his feet forced him to control onto his thigh before he thundered beyond Metcalfe on the half-volley.
Bridge-Wilkinson pointed out some of the minor negatives despite a glowing performance from the forward, "It was good, quite quiet in certain moments but he's always a threat when we can get him the ball and faced towards the goal," He said. "He always going to make things happen, he was pleasing in certain moments again which was good."
Max Woltman continued his goalscoring form with a brace, after his composed spot-kick after 53 minutes, he was back on the scoresheet 11 minutes from time. Despite his first touching seemingly making the avenue on goal unlikely, he manoeuvred space before firing into the top corner.
"Yeah this group of players, the ones who are available and the ones who are injured, we know we can play attacking football we are capable of scoring goals and as we proved in the second half there, if we create the chances then hopefully we'll score some."
Their attention now turns to their last eight fixture on Friday at Anfield, a win would book a spot in the last four against Ipswich Town or Sheffield United.
Marc Bridge-Wilkinson will look to emulate Barry Lewtas' 2019 heroics after they won 5-3 on penalties against Manchester City.
Looking forward to Friday night under the lights, "This games now out the way, we'll be back in Monday and focused on the Arsenal game, I'm looking forward to it." The 42-year-old concluded.