Arsenal lost 3-2 to Brentford on Wednesday, in their second friendly game ahead of the Premier League restart next week.
The Gunners took the lead in the first half through a Joe Willock goal.
However, the Championship side struck three times after the break thanks to goals from Tariqe Fosu, Halil Dervisoglu, and Shandon Baptiste, to stun Mikel Arteta’s men.
Alexandre Lacazette pulled one back for Arsenal, but it was not enough to prevent the North London side from losing.
The Gunners had overpowered Charlton Athletic 5-0 in another friendly played last week at the Emirates.
Arsenal will be traveling to Manchester City on June 17 as the premier league resumes.