The substitute's low finish made it 2-2 on a night of controversy and high drama, and means Arsenal go to Bavaria next Wednesday level in the quarter-final tie but with Bayern narrow favourites, even if away goals no longer count in the Champions League knockout stages.
Arteta can reflect that it might have been so much better for his side had they maintained their composure at the back and turned the screw after Bukayo Saka gave them an early lead, but it could also have been so much worse.
When Leroy Sane raced clear with Bayern leading 2-1 through Serge Gnabry's equaliser and a Harry Kane penalty, it was easy to wonder fleetingly if Arsenal were heading for a humbling defeat.
Luckily, Ben White got back to put off the Bayern winger.
For all their strides forward, the Premier League leaders are still green on this stage, and the match was a classic demonstration that any slip-up will usually be punished by a team such as Bayern, with both the visitors' goals of Arsenal's own making.
Gabriel's loose pass under pressure from Kane was intercepted by Sane, with Jakub Kiwior and Declan Rice both leaden-footed, and Gnabry finished through the legs of a hesitant David Raya against his former club.
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
Why are England wasting time waiting for Tuchel?
Winning the World Cup is the aim, so the new boss should start now
He's been shot, and punched by Mike Tyson, but British boxing's great survivor is back on top and aiming to rule the world
This is where the magic happens,\" reads a big neon sign scrawled across the entrance to the offices of arguably the most powerful man in British boxing today.
How Sketch went from 'obscene' to era-defining
After arocky start, the glamorous and infamous restaurant is now an institution
Money is worth less than time'
He's quit Fendi, but what will Kim Jones do next?
London's Roman Amphitheatre
Guildhall Yard, EC2V
Liberals didn't notice they'd lost relevance in the all-consuming digital sphere
There are many reasons why Donald Trump might have won the election last week.
Do we have to die?
One neuroscientist thinks the answer is no
How to have a magical Christmas in Edinburgh
From cosy cobblestone streets to abundant Yuletide goings-on, few cities rival the Scottish capital in creating Christmas whimsy.
London's best festive restaurants
The social season is upon us once more. These are the city’s most coveted Christmas venues, which need to be booked soon so as to not miss out on the tinsel and tipples.
Rag'n'Bone Man
I struggle with being recognised... I'll never really feel comfortable with it'