Leicester City 2 Arsenal 5

Alexis Sanchez finally opened his account for the season with a stunning hat-trick as the Gunners inflicted Leicester’s first defeat of the campaign.

The Arsenal star had failed to find the net in eight previous appearances – but he made up for that with three goals at the King Power Stadium to lift his side above their hosts and into the top four.

Theo Walcott cancelled out Jamie Vardy’s opener for Leicester before Sanchez’s treble – the first time the Gunners had come from behind to win since their Champions League success at Anderlecht 11 months ago.

And, although Vardy netted again with a consolation strike, it was not enough to deny Arsenal as substitute Olivier Giroud grabbed their fifth goal in injury time.

There were early opportunities at both ends, with an Arsenal break down the left culminating in a low Santi Cazorla shot that was cleared off the line by Ritchie de Laet.

But the Gunners’ back four looked exposed and Jeff Schlupp was allowed the space to hit an angled drive that was beaten away by Petr Cech before Vardy stabbed the loose ball against the post.

Leicester snatched the lead with a counter-attack on 13 minutes as Aaron Ramsey was dispossessed in their penalty area and Danny Drinkwater’s searching pass to the flank found Vardy, who galloped clear to fire across Cech.

Vardy almost made it 2-0 five minutes later, heading Marc Albrighton’s cross against the bar – and immediately Arsenal broke to equalise.

Cazorla crafted an incisive pass for Walcott and the forward, who had already had one attempt saved by Kasper Schmeichel, clipped a left-foot finish beyond the keeper and just inside the far post.

And the visitors went ahead in the 33rd minute when Hector Bellerin’s cross from the right spun up off de Laet and dropped neatly for Sanchez to slam into the unguarded net.

Having belatedly broken his duck for the season, the Chilean playmaker looked eager for more and went close a couple of times at the start of the second half.

And Sanchez did double his tally 12 minutes after the restart, receiving Bellerin’s pass and playing a one-two with Mesut Ozil before nipping in ahead of Schmeichel to nod home the German’s cross.

Walcott could have put the contest beyond doubt, wriggling away from his marker to force a low save from Schmeichel, while Ozil had two efforts deflected over.

But it hardly mattered as Sanchez hammered the final nail into the Foxes’ coffin with 10 minutes left, collecting the ball from a throw-in and rifling a 25-yard crackerjack into the bottom corner.

Leicester found their second wind in the closing stages and Cech foiled Riyad Mahrez and substitute Andrej Kramaric before Vardy blasted in his second of the game.

However, the Gunners had the final word as Nacho Monreal scampered down the left and cut the ball back for Giroud to apply the icing to the cake.

Arsenal: Cech; Bellerin, Mertesacker, Koscielny, Monreal; Flamini (Arteta 21), Cazorla; Ramsey (Oxlade-Chamberlain 77), Ozil, Sanchez; Walcott (Giroud 80).