Leicester moved past MK Dons to reach the Carabao Cup quarter-finals in their first game after the World Cup.
Youri Tielemans and Ayoze Perez gave the Foxes a two-goal cushion at the break before Jamie Vardy added another.
Chances were sporadic for the hosts at Stadium MK and they failed to capitalize on their few opportunities.
Premier League Leicester were a step above and their sharpness in the final third was too much for the League One side to handle.
Thirty-eight days after the Foxes last played a competitive game, Brendan Rodgers’ side didn’t look like a team that lacked precision in games and fired early warning shots through Perez and Timothy Castagne.
Both efforts missed the target, but soon found a way to beat the goalkeeper when Tielemans was on hand to fire home after Jamie Cumming shoved a daring backheel from Vardy into the Belgian’s path.
Leicester’s second came when Perez produced a deft touch inside the penalty area to control a long ball from Luke Thomas before placing a compound effort into the back of the net.
The hosts struggled to make an impression and failed to capitalize on their best chance as Daniel Harvie fired a half-volley over the bar shortly before the break.
Leicester’s dominance increased after the break and Vardy made it three as he nodded into Castagne’s cross to complete the scoring in a one-sided victory.
