A hat-trick from Jonathan De Guzman sent the Swiss side packing and Napoli now look forward to their visit to Florence, in a replay of the 2014 Coppa Italia final, where the Blues triumphed 3-1, back in May.
"It was a great performance from the whole group,'' Benitez told Napoli's official website. "Despite the various changes I made to the team the players expressed themselves at a high level and showed we have a quality squad.
"Now we're going to Florence trying to emulate that same intensity and play the same type of game.
"We have to take each game as it comes, that's the target we have set ourselves and that is what we are pursuing.''
Fiorentina also played in the Europa League this week, though only earning a disappointing 1-1 draw with Greek side PAOK Salonika.
La Viola manager, Vincenzo Montella will be relieved to have Mario Gomez back fit again, the German striker injured since September, as fellow striker Giuseppe Rossi remains sidelined.
Montella has warned the Italian media not to get too excited over the return of the ex-Bayern Munich man however.
"You have to be objective and optimistic with him,'' he told La Gazzetta dello Sport. `"He hasn't enjoyed any continuity in training over the last 18 months and therefore he cannot be the polished article.
"I do expect more from him but I can't judge him on what he is doing right now.''
Team News
Napoli are without on-loan Swansea striker Michu for the long trip up North, while Juan Camilo Zuniga is a doubt at full-back.
Fiorentina won't have the aforementioned Rossi available for selection and Federico Bernardeschi is also injured, meaning both sides are missing valuable players.
Form
Tenth-placed Fiorentina are among the least consistent teams in the league but their last appearance on home turf saw them dole out a 3-0 defeat to early surprise package Udinese.
Napoli, meanwhile, remain two places and one point outside of the final Champions League place having downed title hopefuls Roma 2-0 last time out.