The Gunners went behind to Adam Webster’s opener before Alexandre Lacazette equalized for the hosts, but Frenchman Neal Maupay ensured the visitors took all three points to the Amex Stadium with the winner ten minutes from time.
An air of confusion blew around the Emirates stadium later on in the game when skipper Aubameyang headed straight down the tunnel without being substituted or carrying any sign of injury.
The 30-year-old former Borussia Dortmund striker emerged from the tunnel a couple of minutes later and took his place on the pitch as Arsenal chased an equaliser.
It later emerged that Arsenal’s momentary numerical disadvantage was because their captain had to answer the call of nature.
As the reason for Aubameyang’s disappearance became clearer some Arsenal fans took to Twitter to make their feelings known to their top scorer.
One wrote: “Aubameyang went to take a dump right?”
Another tweeted: “Did Aubameyang just run to the toilet in the middle of the game which we were losing?”
One noted: “Did Aubameyang go to toilet?”
Another added: “And Aubameyang has just emerged from the tunnel. Toilet break?”
Arsenal’s fourth defeat of the season has left them in 10th place on the table.
This is not the first time a Premier League footballer has had to leave the field to attend to nature’s call.
In Mauricio Pochettino’s first game as a Premier League manager for Southampton against Everton in January 2013, Saints forward Jason Puncheon momentarily left the pitch for a toilet break, which left his new manager in stitches.
"Jason was feeling a bit 'unstable' and had to go to the loo,” the future Tottenham Hotspurs manager said at the time.
"It was a nervy day. Whenever there's a new manager, the players want to impress and those nerves can get the better of you."