Manchester United reeled off their third successive Premier League win under new manager Erik ten Hag to ensure Leicester City's troubled start to the season continued at The King Power Stadium.
Jadon Sancho's smooth finish from Marcus Rashford's pass after 23 minutes maintained United's recent revival and allowed them to build on victories against Liverpool and at Southampton.
United remained largely in control against an out of sorts Leicester, who are still searching for their first league win of the season and who, along with manager Brendan Rodgers, felt the impatience of the home fans.
Visiting keeper David de Gea was forced into a fine save from James Maddison's free-kick in the second half but otherwise United were rarely troubled, with Casemiro emerging as a substitute and Cristiano Ronaldo, another late replacement, coming close with an acrobatic bicycle kick.