Noni Madueke headed Arsenal in front on the hour mark, before Keane Lewis-Potter scored a header of his own for the hosts 10 minutes later to settle the scoreline.
Arteta said: “It was a very tough match. We knew that it was very tough to dominate them for the whole game. They are really good at dragging you into the game that they want.
“We struggled the first 10-15 minutes, then we picked it up. In the second half I think we started dominating the game with the pace, the intent that we had, and the amount of situations that we generated, without really hitting the target often enough in my opinion and finishing too many chances. Then we scored the goal and the game was totally controlled.
“After that, you have to stay so disciplined, not to give fouls away. The clearances have to be, especially the balls in the channel, in the right way and the moment you don't do that and you concede the set-piece, a long throw, you have to defend with your life.
“Then you have to maybe defend another set-piece and it's very difficult to get out of that game. Then the game got stretched when they scored and either team could have won it.
"We could have won it with the chance of Gabi (Martinelli) at the end and unfortunately it wasn't enough.”