Germany forward Kai Havertz put Mikel Arteta's side ahead in the first half at the Emirates Stadium and England winger Bukayo Saka wrapped up the points after the interval.
"It was a great action - the whole action, the position, the delivery, the position we had in the box, the way he attacked the ball. It was superb, a great goal," Mikel Arteta told reporters.
"Players need some time to adapt and get to know everybody - the club, the relationships, the system. He’s gained the confidence and the respect of everybody in the way he handles certain situations and in the way he’s performing," he added.