Substitutes Marcus Rashford and Marouane Fellaini both scored as Manchester United overcame a resolute Leicester to strengthen their position at the top of the Premier League.
Jose Mourinho’s side had applied incessant pressure on the Foxes from kick-off, and Romelu Lukaku missed a second-half penalty prior to the goals, as they found it difficult to break the steadfast backline.
They finally breached the last line of defence when Rashford converted Henrikh Mkhitaryan’s corner three minutes after coming on.
And then midfielder Fellaini stuck out his knee to divert fellow substitute Jesse Lingard’s drive past Kasper Schmeichel.
United are the only side to have won all three of their opening league games this season and have yet to concede a goal.
United peppered the opposition area with crosses in the first half, but aside from a Paul Pogba strike that drifted narrowly wide, the threat from the wings was comfortably dealt with by the Foxes’ defensive giants Wes Morgan and Harry Maguire.
There was a shift in manager Mourinho’s thinking in the second half as his side began to breach the 18-yard area with shorter balls from a more central position.
That probing should have resulted in the opening goal. Leicester were once again on the back foot in their area before Anthony Martial struck a shot that came off Danny Simpson’s arm. Referee Michael Oliver declared it to be deliberate handball.
Lukaku stepped up to the spot, but his hopes of a fourth league goal this season were thwarted by Schmeichel’s dive to the right.
Leicester continued to come under pressure and eventually succumbed when Rashford’s instinctive shot flew past the Dane in goal in the 70th minute.
Holes now began to appear in Leicester’s previously watertight defence as they went looking for an equaliser.
United capitalised again as substitute Lingard’s low drive was diverted into the net by Fellaini, although replays suggested the Belgian was fractionally offside.