By Chris Harris
Granit Xhaka was sent off and Pierre-Emerick Aubameyang scored an own goal as we lost in our 400th game at Emirates Stadium.
Our Swiss midfielder was a booked after an altercation with Ashley Westwood, but VAR intervened and referee Graham Scott changed the yellow card to a red.
That stopped us in our tracks after a storming start to the second half, and our woes were compounded when Westwood's corner flicked off Aubameyang's head and flew past Bernd Leno.
It was a miserable turn of events after an hour in which we'd created the vast majority of chances.
The first half was cagey, but we might have had a penalty when Aubameyang's shot was deflected behind by Ben Mee's hand.
Rob Holding flashed a header over from Bukayo Saka's diagonal pass, and Nick Pope made an instinctive save to deny Alex Lacazette after he connected well with Kieran Tierney's cut-back.
Chris Wood squandered a free header from Burnley's most notable attack, but we were largely in control - and we upped the tempo after the break.
Tierney was a regular threat on the left and, after starting an attack, he got into the box to collect Aubameyang's cut-back and test Pope with a low shot.
Aubameyang headed a chance wide and Pope made another fine reaction save to deny Saka after he met Willian's cross-shot.
We were well on top by now, but Xhaka's dismissal checked our progress.
Aubameyang's unfortunate intervention was another huge blow and, although we worked relentlessly with 10 men, we couldn't rescue a point.
HOW IT HAPPENED
WHAT IT MEANS
400 AT EMIRATES
This was our 400th game at Emirates Stadium.
We won our 100th, 200th and 300th games - all without conceding a goal.
Our home record at the stadium now reads: P400 W269 D76 L55 F850 A333
As expected Mikel Arteta fielded a completely different team from the one that lined up at Dundalk on Thursday.
More significantly, there was just one change from the starting XI at Tottenham last weekend, Mohamed Elneny coming in for the injured Thomas Partey.
Emile Smith Rowe came into the squad while Nicolas Pepe served the final match of his Premier League suspension.
We're back at Emirates Stadium on Wednesday to face Southampton in the Premier League.
Then it's Everton at Goodison Park next Saturday.
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