London: A hat-trick by Alexis Sanchez fired Arsenal to a 5-2 win as Leicester`s unbeaten start to the Premier League campaign was ended in emphatic fashion at the King Power Stadium on Saturday.
Sanchez struck on 33, 57 and 81 minutes after Theo Walcott`s 18th-minute equaliser had cancelled out Jamie Vardy`s opener for the hosts five minutes earlier.
Vardy scored again a minute from full time to reduce the Gunners` lead before substitute Olivier Giroud netted in stoppage time to restore the three-goal cushion.
In a high-tempo opening, it was Arsenal who had the first clear chance in the seventh minute.
They exploited the pace of Walcott to get behind the Leicester back four and, when the ball found Santi Cazorla inside the penalty area, his low shot was cleared off the line by Ritchie De Laet.
But the home side responded well and might easily have been ahead twice on 11 minutes.
First Jeffrey Schlupp tore forward from left-back and found himself in the box to unleash a shot that Petr Cech in the Arsenal goal palmed away.
Then Vardy recovered the loose ball, tricked his way into space and saw his curling shot hit the post with Cech beaten.
That merely delayed the opening goal, however, with Vardy netting on 13 minutes.
Wes Morgan made a crunching tackle on Aaron Ramsey inside the Leicester area to trigger a counter-attack, Danny Drinkwater`s excellent crossfield pass found Vardy and he bent a fabulous shot around Cech from a tight angle.
Vardy almost doubled Leicester`s lead moments later when he headed a Marc Albrighton cross against the woodwork.
But Arsenal counter-attacked immediately and grabbed the 18th minute equaliser as Cazorla fed Walcott with a fine ball and the striker sprinted clear and finished superbly off the post.
And the Gunners claimed the lead 11 minutes before half-time after increasing the pressure on the home goal.Leicester claimed both Shinji Okazaki and Vardy had been fouled as Arsenal broke up a Leicester counter-attack, but referee Craig Pawson played on and the visitors took full advantage.
Ramsey`s through-ball was flicked up superbly by Mesut Ozil for Hector Bellerin, whose cross found its way to Sanchez and the Chilean produced an emphatic finish.
Leicester attempted to hit back as half-time approached with Morgan failing to get his head on an Albrighton free-kick before Riyad Mahrez fired just wide from 15 yards.
Arsenal started the second half on top and Robert Huth had to make a vital interception in the Leicester penalty area to block a shot from Sanchez.
Schlupp tried a shot from the edge of the Arsenal box during a rare Leicester attack but it failed to trouble Cech.
And it was no surprise when the Gunners extended their lead on 57 minutes.
Again they caught Leicester with pace on the break and Sanchez found himself unmarked a few yards out to head home Ozil`s delicate chip.
Leicester had a chance to reduce the arrears when Leonardo Ulloa teed up fellow substitute Andy King but he dragged his shot well wide.
But the Gunners continued to dominate and Huth had to make a brave, headed interception to keep out a shot by Ozil.
Sanchez completed his hat-trick with a classy goal on 81 minutes, stepping away from N`Golo Kante and drilling home a right-footed effort from outside the penalty area.
Vardy grabbed his and the Foxes` second goal with a minute remaining.
Andrej Kramaric saw his shot from a Mahrez cross saved by Cech but Ulloa teed up Vardy to bend home another firm shot.
In stoppage time the Gunners struck again as Giroud side-footed home from close range from Nacho Monreal`s cross.