In a fantastic first half for the Foxes, Jamie Vardy opened the scoring after 11 minutes before Riyad Mahrez netted twice, including a penalty, to make it 3-0.
Jermain Defoe replied for the visitors on the hour mark at the King Power but Marc Albrighton soon restored Leicester’s three-goal advantage.
Even though Steven Fletcher gave Sunderland hope with a second goal in the 71st minute, the Foxes held out to secure a well-deserved victory.
Leicester were the form side in the top-flight at the end of last season and despite changing manager in the summer they managed to continue their momentum into the 2015/16 campaign with an impressive display.
Both sides handed debuts to new players, with Shinji Okazaki starting for the Foxes and Younes Kaboul and Jeremain Lens getting the nod for the visitors, who started quite brightly.
Defoe forced an early save from Kasper Schmeichel and Kaboul and Jack Rodwell both saw headers kept out by the Leicester keeper.
But the hosts responded in superb style, taking the lead in the 11th minute when Vardy headed Albrighton’s free-kick across goal and into the far corner.
Mahrez then saw a shot deflected wide before doubling Leicester’s lead on 18 minutes when he flicked in a header from Albrighton’s cross.
The Algerian international soon make it 3-0 as he was brought down in the box by Lee Cattermole and dispatched the subsequent penalty.
Dick Advocaat responded by replacing Cattermole with Fletcher but it failed to give the visitors any foothold in the game before half-time.
Danny Drinkwater almost added a fourth from distance when his effort was palmed away by Pantilimon.
There was little Leicester let-up after the break and Mahrez continued to torment Sunderland as he turned a couple of defenders inside out before hitting the post 10 minutes after the restart.
Pantilimon then saved from Vardy and Mahrez as Leicester threatened to embarrass the visitors.
But they pulled a goal back against the run of play on 60 minutes when Adam Johnson slipped Defoe in to fire into the corner from 10 yards.
Suddenly Defoe was alive and Schmeichel was forced into a smart low save two minutes later.
However, Albrighton restored Leicester’s three-goal lead not long afterwards, firing home when when the visitors failed to clear Mahrez’s cross properly.
The goal rush continued five minutes later when Fletcher made it 4-2, heading into an empty net after Lens lobbed Schmeichel.
It kept the Foxes on their toes but they held on for the win and Okazaki was denied a debut goal by Kaboul’s block with four minutes left.
Soccer Saturday verdict – Paul Merson
Okazaki was very good. He hasn’t got the pace of Vardy, Schlupp or Mahrez but he always holds the ball up. Great touches, great vision. Very impressive and I thought he was different class. Not big, he’s actually quite little but very good.
Kaboul had an absolute shocker at the highest level. He didn’t know what day it was. I don’t know what Tottenham got for him but whatever they got for him… bank it quickly. Sunderland have got players who are going to cause problems to teams at the back. The problem is they’re just going to let in too many goals. They cannot defend and Pantiilimon can hold his head up and walk off because he was very good.
Leicester: Schmeichel (6), De Laet (6), Morgan (5), Huth (5), Schlupp (7), Drinkwater (6), King (6), Albrighton (7), Mahrez (8), Okazaki (7), Vardy (7).
Subs: Kante (5), Fuchs (5), Benalouane (5).
Sunderland: Pantilimon (6), Jones (4), Van Aanholt (5), Kaboul (4), Coates (4), Cattermole (3), Rodwell (4), Larsson (5), Johnson (5), Lens (5), Defoe (6).
Subs: Matthews (5), Fletcher (6).
Man of the match: Riyad Mahrez.