Premier League champions Arsenal met League Two Fleetwood Town at Highbury Stadium in the Carabao Cup on Tuesday (October 27).
The home side went ahead through Aaron Loupalo-Bi in the 21st minute following a slight delay due to an unauthorised drone.
Viktor Gyokeres came off the bench to level things up in the second half with his first goal of the season.
Time ticked by and the game eventually went to penalities. Summer signing Bruno Guimaraes missed the deciding penalty.
Speaking to BBC Radio 5 live after the game, Arteta said: "First of all, congratulations to Fleetwood for going through the next round. The manner that they have done it, and for us a very sad day.
"There is nothing to criticise the players for their attitude, their application. The determination - you could see that was there from the start. Even with 10 men, we conceded a really poor goal to start with that gave them some momentum."