Arsenal forward Alexis Sanchez rediscovered his goal-scoring touch as his hat-trick ended Leicester’s unbeaten start to the season.
Jamie Vardy had put the Foxes ahead with a superb finish from a tight angle after a clinical counter attack.
Theo Walcott equalised when Leicester were themselves caught on the break.
Sanchez then took control of the contest with his treble – the pick his third from long range – as Vardy and Olivier Giroud netted late on.
Sanchez, who scored 25 goals last season for the Gunners, had failed to find the net in eight games across all competitions before this contest.
The result means Leicester are now without a win against Arsenal in 18 Premier League games, stretching back to November 1994.
Meanwhile Tottenham Hotspurs scored a resounding 4-1 win over Manchester City at White Hart Lane.
But Manchester City manager Manuel Pellegrini says two of Spurs’ goals were “clearly offside.
Kevin de Bruyne put City ahead before Eric Dier equalised with a 25-yard shot. Toby Alderweireld then nodded Spurs in front before Harry Kane side-footed his first club goal of the season, with Erik Lamela sliding home a fourth as the visitors chased the game.
Man City have now lost two successive Premier League games, having won the previous 11 in a row.