Leicester kept alive their play-off hopes but dented Burnley's fading chances of a top-six finish with a comprehensive victory.
Diomansy Kamara smashed the opener on his home debut and was fouled by Andre Bikey for a penalty that Paul Gallagher converted.
Gallagher then made certain of the points with a fierce 25-yard strike.
Patrick van Aanholt struck with a curling effort before Richie Wellens hit the crossbar.
The result leaves Sven-Goran Eriksson's Foxes five points off sixth place in the Championship with six games of the regular season remaining.
But Eddie Howe's Clarets are now seven points adrift of a play-off spot and in a run of poor form in which they have lost four of their last five matches.
Howe made four changes from the team that lost 2-1 against Ipswich in their last game, with Brian Jensen, Wade Elliott, Chris Iwelumo and Michael Duff all brought into the side to try to bring about a change of form.
But they might have conceded inside two minutes when Kamara almost connected with a cross from Gallagher.
Burnley striker Nathan Delfouneso saw a 25-yard strike take a deflection that almost undid keeper Chris Weale.
But Leicester opened the scoring after Kamara nicked the ball off the toes of team-mate Yakubu before shooting home.
Burnley's Tyrone Mears failed to find the target after the break, seconds after Weale spilled a Delfouneso cross.
But the Foxes took the game beyond their opponents when Gallagher struck from the spot.
Gallagher then ended a superb surging run with his second of the afternoon before Van Aanholt completed the scoring.