A Wilfred Ndidi own goal in the 94th minute and a close-range Kai Havertz strike in the ninth minute of stoppage time denied a Foxes side who were within reach of an unlikely point at Emirates Stadium after clawing back a two-goal deficit in the second half.
Gabriel Martinelli had given the dominant Gunners a deserved first-half lead when he steered home Jurrien Timber’s cross, before providing the pass for the second, converted by Leandro Trossard, on the stroke of half-time.
Leicester had managed only one touch in the Arsenal area before the break, but they reduced the arrears a little over a minute into the second half when James Justin’s header from Facundo Buonanotte’s free-kick struck Havertz on its way in.
Justin doubled his personal tally in spectacular fashion shortly after the hour mark, meeting Ndidi’s left-wing delivery with a swerving volley that beat David Raya via the inside of the post.
If Arsenal were momentarily stunned by Leicester’s recovery, they soon recovered their poise and Mads Hermansen produced two superb saves to keep the Foxes level, denying Havertz with a point-blank stop before keeping out Trossard’s shot – moments after giving the ball away inside his own area.
But Trossard’s late effort was deflected past the Danish goalkeeper by Ndidi before Havertz struck from close-range to complete the scoring.
Victory lifts Arsenal level on points with Manchester City, who could be overtaken by Liverpool if they beat Wolves at Molineux in Saturday’s late game.
Arsenal fans must have been scratching their heads as the game entered second-half stoppage time, as Leicester closed in on a draw that had barely seemed possible at the halfway point of the contest.
Notwithstanding a Justin shot which was blocked by Riccardo Calafiori, the first 45 minutes took place almost entirely inside the Leicester half, with Bukayo Saka and Martinelli both going close before the Brazilian’s 20th-minute opener.
Calafiori stung Hermansen’s palms and Havertz sent a header narrowly wide from Trossard’s cross, before the Belgian – back from suspension after his dismissal against City last weekend – gave the home side a richly deserved two-goal cushion.
Justin’s first of the afternoon came almost out of nothing and, buoyed by his header, the Foxes continued to venture forward and eventually restored parity through the defender’s spectacular swerving strike.
Time appeared to be running out for Arteta’s team, who had registered more than 30 shots – including 14 on target – and racked up 14 corners as the clock ticked past 90 minutes.
Hermansen did brilliantly to keep out goalbound efforts from Havertz and Trossard before denying Calafiori and substitute Ethan Nwaneri as the Gunners piled forward in increasing desperation.
But they were finally rewarded for their pressure and persistence with just over three of the allotted seven minutes of added time remaining, before Havertz completed the scoring with virtually the final touch of the game.
Pain for Foxes, but positives for Cooper
Steve Cooper said he would not shy away from criticism after Leicester fans were heard chanting “Cooper, sort it out” and “this is embarrassing” during Tuesday’s penalty shootout victory at Walsall in the Carabao Cup.
At half-time on Saturday, it looked like being another painful afternoon for the Foxes and their manager as Arsenal sailed serenely into a two-goal lead, but Leicester’s second-half recovery – though ultimately in vain – will give fans heart for the battles ahead.
Cooper’s team were vastly improved after the restart and Justin’s sensational drive will live long in the memories of the away fans nestled in the lower tier of the Emirates Stadium’s south east corner.
Hermansen was sensational in the latter stages, producing a string of fine saves to keep Arsenal at bay – but there was little he could do about Ndidi’s own goal or Havertz’s last-gasp effort.
Not for the first time this season, Cooper was frustrated by some of the officiating at Emirates Stadium, with referee Sam Barrott refusing to penalise William Saliba for a tug on Jamie Vardy in the build-up to Martinelli’s opener.
Cooper and Vardy were both booked after remonstrating with the officials in the aftermath of the goal.
Once the dust settles on this pulsating contest, Cooper can reflect with pride on his team’s fightback against one of the Premier League’s title challengers – but the manner of the defeat may take a while to digest.