Arsenal currently top Group F in the competition as well as the Premier League, and Giroud feels that they deserve to be where they are.
"We knew the quality of Napoli so we did really well from the start of the first half and succeeded in scoring twice," Giroud told the media. "At half time we wanted to keep it up and managed to keep the ball and play our game. We are really proud of our first half and the whole game and we deserved it, I think.
"The team is playing well and we are on a good run. Mesut especially tonight was unbelievable. It is really simple to find him on the pitch and I have a really good understanding with him. He [provided] the assist for my goal. He knows [to do] the right thing at the right moment. This is his first goal, but he has provided a lot. I think it was his fifth or sixth assist since he joined. He was the man we needed to really improve our side.
"Since the start of the season I maybe have more confidence and I am settling well now, in the team and in my new English life. I feel really good on the pitch and really want to improve myself and the team. We took a lot of pleasure [from the performance] and that is the most important [thing].
"We always want to win and to keep this mentality of winning every game. [Borussia Dortmund] will be really tough games for us but we are really confident and if we keep it up, I think we could do good things in this Champions League."
Arsenal travel to West Bromwich Albion on Sunday.