Alexandre Lacazette scored inside two minutes heading in superbly from Mohamed Elneny's pinpoint cross.
Leicester's responded as Shinji Okazaki nodded in from Harry Maguire's headed cut-back three minutes later.
Marc Albrighton's low ball across goal split Arsenal's defence and was dispatched in style by Jamie Vardy.
Danny Welbeck equalised in first half stoppage time after selfless play from Sead Kolasinac cutting ball back.
Striker Vardy restored Leicester's lead with a glancing header from Riyad Mahrez's corner after 55 minutes.
Contest changed on substitutions as Aaron Ramsey and Olivier Giroud scored just three minutes apart.