The Spain international continued a fine start up front for the Blues while Didier Drogba came on to make his return to the club in a comfortable win at Stamford Bridge
In their first home match of the campaign, the Foxes held out in the first half before the Blues' quality told after the interval.
Diego Costa netted a poacher's finish to break the deadlock before Eden Hazard doubled the advantage for Jose Mourinho's side with a fine strike that deflected off Wes Morgan.
Though Jose Mourinho's title hopefuls turned in a dazzling display to beat Burnley 3-1 in their opening fixture, with Costa starring, they found another newly promoted team a far tougher nut to crack on Saturday.
|VIEW FROM STAMFORD BRIDGE
|By Liam Twomey
It became a reasonably comfortable win for Chelsea but this match should be remembered as the moment when Thibaut Courtois really began to stake his claim to Petr Cech's long-held No.1 spot. The Belgian had little to do in a turgid first half but produced two excellent saves to deny David Nugent in the second, including a one-on-one stop at 0-0 in which his sheer presence seemed to intimidate the Leicester City striker. It proved the game's decisive moment.
Diego Costa continued his effortless start to life in English football with a predatory finish to break the deadlock and Eden Hazard made up for a largely uninspired display by sealing the win late on. Chelsea still look as if they have several more gears to reach this season - a fact that will make their rivals even more concerned by their 100 per cent start.
Leicester were impressive and frustrated their illustrious opponents for 45 minutes. That is no mean feat and, while Nigel Pearson leaves London with no points to show for his team's effort, this performance should reinforce his belief that, despite their lack of star names, the Foxes can survive and establish themselves in this league.
The hosts pushed forward early on and Cesc Fabregas - who had performed a star turn on his debut at Burnley - played in Costa to set up Andre Schurrle in the eighth minute but the Germany international shot over. Gary Cahill then had a shot blocked when Schmeichel flapped at a 20th-minute corner.
Nevertheless, the visitors made a confident start as Nugent, Jeffrey Schlupp and Riyad Mahrez all asked questions of the Chelsea defence.
Schurrle headed over when a previously low-key Hazard shimmied his way to the byeline, before Mahrez's own nifty footwork left Cesar Azpilicueta in his wake and created enough room for the winger to fire in a rasping 32nd-minute drive that Courtois had to beat away to safety.
The impressive Mahrez was guilty of overplaying as Azpilicueta snuffed out another promising attack and Chelsea responded, with City centre-back Morgan flinging himself forward to divert Costa's 36th-minute strike over the crossbar.
Oscar clipped an 18-yard effort against the the inside of post three minutes after half-time and, as Chelsea kept the ball alive, Ivanovic headed goalwards from Azpilicueta's cross to draw a fine stop from Schmeichel.
Courtois then found himself back in action to keep out Nugent's deflected attempt on the counterattack, although the sight of Schurrle curling a shot over the crossbar underlined Chelsea's continued threat.
Oscar had a 54th-minute penalty claim for handball rejected and, a few seconds later, Ivanovic hammered in a shot from distance to extend Schmeichel once more. Again, though, Courtois was forced to outdo his opposite number, saving superbly after Nugent had raced clear one-on-one only to produce a shot that lacked conviction.
Schmeichel still appeared destined to be the busier of the two, clawing Fabregas's dinked chip behind in the 58th minute before Leicester's resistance was finally broken five minutes later. Oscar sent Ivanovic racing into the City box and he found Costa, who scrambled the ball home under pressure.
Leicester faded as an attacking force thereafter while Chelsea introduced Didier Drogba late on for his second home Premier League bow.
But, despite seeing Hazard jink beyond substitute Marc Albrighton to rifle in a 77th-minute finish in some style, Leicester boss Nigel Pearson was given plenty of reason to be optimistic for the challenges ahead.
Chelsea, meanwhile, already look every bit title challengers.