Summer signing Sánchez netted from close range in the 20th minute after Yaya Sanogo had bundled the ball past keeper Kasper Schmeichel.
However, the Gunners’ lead lasted less than two minutes before Argentine Leonardo Ulloa climbed above Laurent Koscielny to head in.
The draw left Arsenal seventh in the Premier League on five points after three games.
The match inevitably prompted plenty of activity on Twitter – and here are some our favourite updates.
Ray Parlour (@RealRomfordPele) tweets his delight as his former side take the lead: “Yes. Get in Sanchez with the opener 1 0 #gooners”
England legend Gary Lineker (@GaryLineker) points out Sanogo’s mistake before the opener: “Sanogo’s ineptitude inadvertently leads to a Sanchez goal. #sourgrapestweet”
But it isn’t long before the home side draw level, with Matt Le Tissier (@mattletiss7) tweeting: “This Leicester team have got some cojones”
Parlour (@RealRomfordPele) reluctantly praises the goal-scorer: “Equaliser for Leicester. Great header Ulloa 1-1”
Former Tottenham chairman Lord Sugar (@Lord_Sugar) would love a home win: “No disrespect, I assumed Leicester will get done by Arsenal. nothing would delight me more than stuffing the Gooners”
Lineker (@GaryLineker) gives his post-match thoughts: “Absolutely brilliant performance from @OfficialFOXES . 2 points from Everton, Chelsea and Arsenal is a superb start. As for Arsenal, if Wenger doesn’t bring in a decent striker even 4th place might elude them this season.”
And finally, celebrity Arsenal fan Piers Morgan (@piersmorgan) has the last word: “Sign. A. Bloody. Striker. Wenger. Every single Arsenal fan knows we need a top class striker & CDM. If Wenger refuses to buy them, he is defying the whole fan base. #afc”
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