The Gunners were outclassed in a 3-0 Premier League defeat to Brighton on September 19 - which the Spaniard described as was 'very painful.'
Goals from Pascal Gross, Charalampos Kostoulas, and Chema Andres secured three points for the home side, who now climb up to third, as Arsenal head into the international break with their 100% record broken.
Manchester City can overtake them with a positive result against Sunderland this weekend and Arteta admitted his team lacked respect for the game at the AMEX Stadium.
"A very disappointing result and performance. Full credit to Brighton in the manner they performed and went about the game.
"We have to make sure we learn the lesson because this can't happen again.
"When we had the ball, especially in our own half, we were extremely poor technically, not respecting the game and the game principles you have to apply against a team that want to press you man to man."