Martin Odegaard struck an opener for Arsenal before Georginio Rutter put through his own net to double Arsenal's lead. However, Diego Gomez's goal midway through the second-half kept Arsenal on their toes for the remainder of the game.
Arteta said afterwards: "I thought we were very dominant throughout the game.
"We generated so many chances, so many big situations and I think we did a lot of great things where I think the margin should have been much bigger than 2-0. But when you don't do that, teams have quality, they have a lot of individual quality, and they score the goal, then it's game on.
"But overall, after playing every three days, the performance that the boys put in today, with all the difficult situations we're going through, again, especially in the backline, we lost Jurrien (Timber) yesterday, we lost (Riccardo) Calafiori today in the warm-up, the way the boys step up to the task.
"When Declan (Rice) is on as a right full-back, it's just unbelievable, and I'm so proud of them. (Rice at right-back) is a really good example to describe how I feel about the team and the spirit, and the willingness to win of this team.
"We're going to need everybody, some who are in a different position and to go through what we are going through in the manner that we are performing. It's great to witness."