Nathaniel Clyne, Rhian Brewster (two), Curtis Jones, Divock Origi and Bobby Duncan were the goalscorers as Jürgen Klopp’s side kicked off their seven-game build-up to the campaign in emphatic fashion.
The manager gave minutes to 23 players at Prenton Park in front of a sell-out crowd for the meeting with the League One team.
An energetic beginning to the contest was punctuated by Liverpool’s first goal of 2019-20 with just six minutes on the clock.
Its genesis was a surging run from his own half by Joe Gomez, whose eventual pass into Brewster was swiftly turned out to the right channel for Clyne to dispatch an excellent rising finish high into the Tranmere net.
Watch: Clyne slams in opening goal
Gomez soon had to make amends for a misjudgement in possession in his own half, the No.12 recovering to block a firm shot after Paul Mullin had broken into the box and stepped into a prime central position to score.
The lively Yasser Larouci, so often an out ball at left-back, was unlucky to see a 10th-minute drive deflected over after a sweet one-two with Adam Lallana.
The 18-year-old later saw another decent effort, this one angled across goal from the left side, stopped and at the other end Simon Mignolet carefully kept out a bouncing strike from Corey Blackett-Taylor.
Liverpool continued to move the ball quickly and intelligently – and their pressure told with a Brewster double before the break.
First, James Milner’s dangerous cross from the left reached Harry Wilson at the opposite post and the Welshman knocked it back into the middle, where Brewster nodded home.
And the No.24 further increased the Reds’ advantage with the last real action of the first half. Milner’s effort on the turn at the edge of the area was palmed out into Brewster’s path for a straightforward tap-in and 3-0.
Watch: Brewster heads in Liverpool second
Watch: Brewster on the rebound for Reds' third
As planned, Klopp changed his entire XI at half-time, with Duncan, Paul Glatzel, George Johnston and Adam Lewis among the youngsters handed a chance to impress.
It was another of the club’s emerging Academy prospects that bagged Liverpool’s fourth goal of the evening.
Origi held the ball up strongly in the right channel and fed it back to Ben Woodburn, who curled a cross to the far post for Jones to successfully place a finish past the goalkeeper on the stretch.
Then, a day after signing a new long-term Reds contract, Champions League hero Origi got back in the goals with an unerring touch, dribble around the goalkeeper and slot home on the hour.
Watch: Jones stretches to score fourth
Watch: Fine touch and finish from Origi
Duncan wrapped up the night’s scoring with a neat tuck into the net after Ki-Jana Hoever sliced through the Tranmere defence and Glatzel moved the ball on to his U18s strike partner of last term.
Glatzel was frustratingly forced off with an injury a quarter an hour from time, prompting the introduction of Academy goalkeeper Daniel Atherton in a forward role – the only negative of an encouraging outing for Klopp’s men.