Marcus Rashford's early goal for Manchester United was enough to edge Leicester City at the King Power Stadium.
Rashford controlled brilliantly after a fine Paul Pogba pass to fire past Kasper Schmeichel just nine minutes in.
The victory is Ole Gunnar Solksjaer's ninth win in just 10 games as interim Manchester United boss.
Image via @PremierLeague
Rashford had a glorious chance to open the scoring on five minutes, after only being able to divert Luke Shaw's fine cross wide.
However, the 21-year-old, who was making his 100th Premier League appearance for United, killed the ball after a lofted Pogba through-ball and fired past Schmeichel. Fantastic goal from United.
Leicester were pressuring the visitors, but they couldn't seem to test David de Gea in the United goal.
But after the restart, the Foxes did manage to threaten a bit more. Harvey Barnes' effort was tipped away from the Spanish goalkeeper.
James Maddison's free-kick was blocked but only as far as Jamie Vardy - whose acrobatic effort was straight at de Gea.
Substitute Rachid Ghezzal also tested the 'keeper when his free-kick from 30 yards was excellently saved.
Jonny Evans had an opportunity to score against his former side, but the Northern Ireland defender couldn't make clean contact with the ball.
Solksjaer brought on Anthony Martial and Romelu Lukaku in the closing stages of the match to try and take advantage of Leicester's attackers being up-front.
But the score stayed the same. For Solksjaer, his unbeaten start as United boss continues and so does their pursuit for a UEFA Champions League place.
Image via @PremierLeague
The Managers
Leicester City boss Claude Puel: "We started the game with a poor performance and without intensity. It was a shame.
"In the second-half, we showed a lot of things with more desire and quality in our play. We put them under pressure at the end of the game but it was not enough."
Manchester United interim manager Ole Gunnar Solksjaer: "Our attitude was spot on. There are a couple of bruised noses and knees.
"It is supposed to be like this. There are three points on the line. Our lads sacrificed everything they had. They know they can do better than this but a clean sheet is always a foundation to build on."