Danny Welbeck's last-gasp winner saw Arsenal come from behind to defeat 10-man Leicester City 2-1 at Emirates Stadium, moving them to within two points of the leaders in the Premier League title race.
Jamie Vardy won and converted a penalty on the stroke of half-time, but Danny Simpson was sent off for a second booking early in the second half in an incident that changed the game.
The Gunners capitalised when substitute Theo Walcott equalised with 20 minutes remaining and sealed a dramatic victory through the returning Welbeck - off the bench to make his first appearance since April - as he headed home in the fifth minute of stoppage time.
Leicester's defeat is only their third of the league campaign, while Arsenal's second straight victory puts them within striking distance of the top of the table ahead of the meeting between title rivals Manchester City and Tottenham.
Arsenal had a half-hearted penalty claim turn down after Alex Oxlade-Chamberlain's cross struck the arm of N'Golo Kante from close range, but it was the visitors - unchanged for the sixth straight game - who created the first major opportunity.
Marc Albrighton delivered a threatening cross from the right channel and Vardy got up at the back post to head towards the bottom corner, but Petr Cech reacted superbly to get down and save.
Arsenal striker Olivier Giroud was correctly denied by an offside flag after heading in Mesut Ozil's inviting cross, while Cech clawed away a curling attempt from Kante that was swerving dangerously towards the top corner in an end-to-end encounter.
Leicester made the breakthrough in the last minute of the first half when a trademark counter-attack led to Vardy being clumsily brought down by Nacho Monreal in the corner of the box.
Vardy took the penalty himself and hammered his attempt into the bottom-right corner, sending Cech the wrong way.
Arsenal, already without the injured Gabriel, had to replace Laurent Koscielny at half-time as Calum Chambers came on and they were relieved to see the visitors have a penalty claim turned down when Riyad Mahrez went down under pressure from Monreal.
The game took a crucial turn in the 54th minute when Simpson was shown a second yellow card for tugging back Giroud, just five minutes after fouling Alexis Sanchez to pick up his initial booking - the first time Leicester had been reduced to 10 men in the league this season.
It was Arsenal's first shot on target that gave them the equaliser. Hector Bellerin's cross from the right was cleverly headed on by Giroud and Walcott beat Kasper Schmeichel with a cool finish nine minutes after coming on.
Danny Drinkwater was fortunate not to be penalised for a high challenge on Aaron Ramsey a few moments later, before Welbeck made his comeback from the substitutes' bench.
Arsenal pressed hard for a late winner, with Per Mertesacker heading inches wide and Giroud being thwarted by an excellent reflex save from Schmeichel.
And the breakthrough arrived when Ozil's perfectly flighted free-kick was converted by Welbeck, sending the home crowd wild.
Key Opta Stats:
- Leicester City have not won a league game against Arsenal since November 1994 (P19 W0 D6 L13).
- Jamie Vardy has won six penalties in the Premier League this season; twice as many as any other player.
- Leicester City have been awarded 10 penalties this season in the Premier League - twice as many as any other team.
- Theo Walcott's 70th-minute goal was Arsenal-s first shot on target in this match, while Danny Welbeck scored their sixth and final shot on target in this game.
- Welbeck's goal was Arsenal's 100th scored past the 90-minute mark of a Premier League game; more than any other side.