A familiar foe scored one and made the other to extend our disappointing run in the Premier League.
Jamie Vardy broke the deadlock in the second half with his ninth goal from nine appearances against us, then set up the second for James Maddison to seal our fate and make it four league games without a win.
We were happy to concede possession in the first half, standing off whenever Leicester had the ball in their own half. But we were living dangerously at times when the hosts did break forward.
Vardy would have had a tap in early on but for the attentions of Calum Chambers, while Harvey Barnes was well off target with his header from an inviting cross.
As for us, Alexandre Lacazette had two or three decent chances, often created when Hector Bellerin sprung forward from the back, but each time his finishing let him down, failing to make good contact with a good low cross into the area after 20 minutes.
But there were promising signs from an attacking sense, and we started the second half in a positive fashion, but not before a suffering a scare when Wilfred Ndidi struck the bar when well placed.
David Luiz and Bellerin both had shots just off target before Aubameyang did put the ball in the net, only to be flagged offside.
The game was much more open now, and it was Leicester who took advantage, when Vardy crisply finished a well worked move into the box.
Leno made a good save to prevent Vardy doubling the lead but he could do nothing about James Maddison's low shot with 15 minutes remaining, that nestled in the bottom corner.
There was no reaction from us in an attacking sense, and it was Leicester who came closest to scoring again in the final stages.
HOW IT HAPPENED
Unai Emery stuck with a back three after reverting to that formation for the midweek draw with Vitoria in the Europa League.
It meant Rob Holding and Hector Bellerin both came in for their first Premier League appearances of the season, and the side showed three changes in all from the side that drew 1-1 with Wolves last weekend, with Sead Kolasinac replacing Kieran Tierney.
Alexandre Lacazette and Pierre-Emerick Aubameyang started up front with Mesut Ozil operating behind them in the number 10 role.
WHAT IT MEANS
We now have two weeks without a game as our international players will join up with their countries for the latest round of qualifiers and friendlies.
We're back in action on Saturday, November 23, with a home game against Southampton, followed by a Europa League tie against Eintracht Frankfurt at the Emirates.
Copyright 2023 The Arsenal Football Club Limited. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source.