Leicester City 2 Peterborough United 0
Wes Morgan put the Foxes ahead after the break with a powerful header from Ben Marshall's corner kick, before Andy King came off the bench to double the lead with a fine strike with fifteen minutes remaining.
Peterborough's best chances came late on in the match through substitute Emile Sinclair, but the former Macclesfield forward was less than clinical when presented with the opportunity to get his team back into the match.
Leicester are likely to face tougher tests this season, but it was certainly a good benchmark for Nigel Pearson's side who are, once again, heavily tipped by bookmakers to win promotion to the Premier League after an absence of eight seasons from the top flight.
Nigel Pearson named an unchanged starting eleven from the side that won 4-0 at Torquay United in the first round of the Capital One Cup in midweek - but it was Peterborough who had the first chance of the match when Lee Tomlin's strike from distance was tipped round the post by Kasper Schmeichel.
Leicester looked sharp in the early exchanges; most notably Jermaine Beckford who willingly chased down every loose ball and seemed determined to menace Peterborough's defence, while Ben Marshall's set pieces continued to trouble the visiting side.
Ritchie De Laet headed just wide from a Ben Marshall free-kick, before new signing Jamie Vardy scuffed a volley after Jermaine Beckford had cleverly nodded the ball into his path.
Leicester looked strong at the back, too, as new captain Wes Morgan accompanied by youngster Liam Moore at centre-back, who performed admirably in his first senior home game for the club.
Peterborough rarely threatened in the first-half, and could have fallen behind when Jamie Vardy's low pass towards Jermaine Beckford almost resulted in an own goal when Posh defender Gabriel Zakuani almost put the ball into his own net.
Jermaine Beckford headed centimetres wide five minutes before half-time, before Lloyd Dyer's trickery resulted in a fine cross into the box, but there was no blue shirt on hand to tuck the ball away.
After the break, Kasper Schmeichel showed good awareness to parry Paul Taylor's powerful strike, but the hosts were ahead just minutes later when Ben Marshall's corner was met with a strong header from Wes Morgan which flew off the underside of the crossbar and into the net.
It was Morgan's first goal as a Leicester City player and a great way to kick-off his captaincy for the Foxes, although Darren Ferguson may argue that Gabriel Zakuani was fouled in build-up.
Leicester began to play somewhat more confidently after going a goal ahead, and both Jamie Vardy and Lloyd Dyer came close to doubling the Foxes' advantage just moments after the goal.
At the other end, Peterborough substitute Emile Sinclair inexplicably fired over the bar after good work on the right-hand side of the pitch when it seemed easier to hit the target.
Peterborough were left to rue that missed opportunity as Leicester broke through the middle minutes later, and when Jamie Vardy picked out substitute Andy King on the edge of the penalty area, the Welsh international fired home superbly from 20 yards to put the Foxes 2-0 ahead and secure the three points.
It was a wonderful finish from the midfielder, who will be hoping for more appearances in the starting eleven if he continues to make an impact when given the opportunity to do so.
Leicester, who were, by now, coasting, could have seen their two-goal advantage dissipate when Emile Sinclair again found his way into the opposing penalty area, but his tame effort was easily collected by Kasper Schmeichel.
With just less than ten minutes to go, Sinclair managed to beat Wes Morgan to the ball and tried to curl a shot into the far corner, but again, the Danish shot stopper would not be beaten.
The second-half fizzled out after four minutes of stoppage time, and the final whistle gave Leicester all three points to get the season off to the best start possible at the King Power Stadium.
Man of the Match - Wes Morgan