The Gunners must now lift themselves for Saturday's trip to Swansea as they look to chase a Champions League place for next season.
"It has to give us confidence, but we must keep our feet on the Earth as well because we haven't been on the consistency [level] that is required at this football club," said Arteta.
"On Saturday, if we are not at it, we are going to face a really difficult team which is Swansea away from home."
Arteta added: "For us it (Champions League) is massive, for the club and the fans, we cannot afford to be out of the Champions League.
"You never know in football. We have to focus on us. At the moment it doesn't depend on us, but the only thing we can do is win every game."