Ahead of their trip to Arsenal on Tuesday, Benitez feels that the squad has strengthened sufficiently over the summer to compete for major honours.
"It's the opposite thing [to the first game against Dortmund] – now we need to control the euphoria, we are going to play against a top side and we must show character, strength [and also] respect to a team that is top of the league and playing very well," Benitez said in his press conference.
"I was expecting a strong [Arsenal] team because I think Wenger is the top coach in the Premier League, and then they signed top players so it's going well for them.
"My idea is always to take it one game at a time. Now my priority is the Champions League and on Sunday it will be Serie A. At the moment we have a strong enough squad to challenge for both."
Napoli make the trip to Arsenal in the Champions League on Tuesday night.