Aside from an early opening in which Jamie Vardy forced a save from Andre Onana with a poked effort, there was little in the way of notable action during a low-key start to proceedings.
The first half eventually sprung to life when Christian Eriksen struck the far post with a whipped first-time shot, shortly before Patson Daka appeared to be racing through on goal at the other end, only to be denied by a timely recovery tackle from Heaven.
Increasingly integral to Ruben Amorim’s United, Bruno Fernandes was the architect when the visitors made the breakthrough in the 28th minute, expertly picking out Rasmus Hojlund, who carried the ball towards goal and finished clinically with his weaker foot – his first goal of 2025.
United remained largely in control until half-time, but there were reminders of Leicester’s often absent attacking threat, with Manuel Ugarte making a crucial interception to deny Wilfred Ndidi and Daka seeing his fierce shot blocked by Heaven.
Having acquitted himself incredibly well on his full league debut, 18-year-old Heaven was unfortunately forced off on a stretcher shortly after the restart.
With no centre-backs available on the bench, midfielder Toby Collyer was his replacement, but the reshuffle didn’t seem to affect United as they found the net for a second time.
Alejandro Garnacho’s celebrations were swiftly cut short though, having strayed offside before neatly tucking home from inside the box.
However, 10 minutes later the Argentine wouldn’t be prevented from doubling the visitors’ lead, catching out Mads Hermansen with a snapshot from a similar position to score for the first time since November.
With the points already in the bag, Fernandes got his name on the scoresheet with his third goal involvement of the night, and his eighth against Leicester this season, tucking in from the edge of the box.
Having lost to United twice when Van Nistelrooy was in the opposite dugout, this result marks a fourth head-to-head defeat of the season for Leicester – just the second time they have ever lost to the same opponent four times in a single campaign.
A 13th PL defeat in 14 matches and results elsewhere leave them nine points from safety in 19th, while the Red Devils climb to 13th, with the mood perhaps beginning to lift following their midweek UEFA Europa League progression.
Flashscore Man of the Match: Bruno Fernandes (Manchester United)