A clinical first-half passage of play effectively won the contest as Darwin Nunez (30), Bobby Clark (35) and Diogo Jota (38) found the target in rapid succession.
Ben Doak increased the Reds’ lead further midway through the second half and ensured Jürgen Klopp’s team once again collected the Standard Chartered Singapore Trophy that they had won last summer.
The opener of two fixtures on their tour of Singapore saw Liverpool emerge at the National Stadium wearing their new 2023-24 away kit for the first time.
Leicester set about trying to dampen the spirits of a majority Reds crowd and Marc Albrighton hooked a cross-shot wide of the far post when worked into space along the right.
Enzo Maresca’s team then created a much clearer chance as Kasey McAteer nudged a well-judged diagonal pass into the box for the run of Wilfred Ndidi. But Caoimhin Kelleher was quick from his line to diligently block the midfielder’s finish.
An offside flag denied Nunez after he had hooked the ball past goalkeeper Mads Hermansen and tapped home, while Ibrahima Konate had to get across the area to snuff out a decent sight of the net for McAteer.
Hermansen clawed away a low curler from Mohamed Salah and would soon make a similar save, though this time it was not enough to thwart Liverpool.
Jota cutely turned on Alexis Mac Allister’s pass into the left side of the Leicester area and when his low hit across goal was parried by Hermansen, there was Nunez to thrash a finish high into the net for 1-0.
The Reds trebled that advantage shortly after with two goals in three minutes.
First, Salah capitalised on a pocket of space to stand up his marker as he dribbled into the box and then shift the ball left to Clark, who threaded a good low shot inside the left post.
Salah claimed a quickfire second assist when, from a comparable position in off the wing, he swept a cross into the middle that was glanced past Hermansen by the head of Jota.
Klopp deployed 10 changes for the second half, with only Kelleher continuing, while Dominik Szoboszlai was back after a brief injury lay-off.
Harvey Elliott and Cody Gakpo, twice, swiftly had efforts blocked and James McConnell sent a crisp drive whistling just the wrong side of the post from 20 yards.
Liverpool were firmly on top and keen on a fourth goal, with Luis Diaz the next to threaten – the Colombia international was blocked out having created a yard and fired goalwards.
When Hermansen was caught out of goal just past the hour, Szoboszlai almost added to the scoresheet in cheeky fashion with a lob from long distance that the Leicester ’keeper scurried back to unconventionally head away.
The Reds did extend their lead on 64 minutes, though. A corner from the left flank was flicked on at the near post by Joel Matip and fell to Doak to convert from close range.
Hermansen pushed out a Gakpo attempt from the edge of the box that could have found the bottom left corner, before the Foxes threatened twice.
A counter-attack caused a scramble in Liverpool territory and as Patson Daka was primed to hit the net, Jarell Quansah repelled him with a brilliant last-ditch tackle. On the follow-up, Kiernan Dewsbury-Hall was inches wide with an angled strike across Alisson Becker.
But it remained 4-0 to Liverpool, who now look forward to a meeting with Bayern Munich back at the same venue on Wednesday.
First half: Kelleher, Alexander-Arnold, Konate, Van Dijk, Robertson, Jones, Clark, Mac Allister, Jota, Salah, Nunez.
Second half: Kelleher (Alisson, 60), Gomez, Matip, Quansah (Frauendorf, 86), Tsimikas, McConnell, Elliott, Szoboszlai (Scanlon, 80), Doak, Diaz, Gakpo.