Benitez was able to enjoy his debut for Napoli as last season's runners-up began life without Edinson Cavani by over-running Bologna with two goals from Marek Hamsik and one from Spaniard Jose Callejon who was making his debut.
There was plenty for Benitez to celebrate at Napoli as Gonzalo Higuain also made an impressive debut following his move from Real Madrid while Pepe Reina in goal was barely tested.
"I saw perfect training sessions and expected this sort of match from my men," Benitez, whose lasted only six months as coach of Inter Milan on his only previous venture into Italian football, told Sky Sports Italia.
"This team has a lot of quality and in attack we can use any combination of (Goran) Pandev, Hamsik, Higuain, Callejon and (Lorenzo) Insigne, as well as another striker. We have the capability to change things around often."
Callejon hit the post early on and put Napoli ahead in the 32nd minute from a rebound after Hamsik's shot had been saved.
Higuain had a goal ruled out for offside shortly afterwards before Hamsik scored a brilliant second, slaloming his way through the defence before scoring from a narrow angle despite being off-balance.
Although Napoli slowed after the break, they were still in control and Hamsik turned in Goran Pandev's cross just after the hour for their third.
Cagliari, unable to find a suitable venue in Sardinia, played their home game against Atalanta in Trieste on the border with Slovenia, around 1,000 kilometres from their base.
They nevertheless won the game 2-1.
AS Roma gave Rudi Garcia a winning start by beating promoted Livorno 2-0 away.
The hosts held their own for an hour until Daniele De Rossi broke the deadlock on 65 minutes and the game was put to bed two minutes later as Alessandro Florenzi doubled his side's lead.
Lazio secured a 2-1 win over Udinese thanks to two goals in the opening 20 minutes.
Hernanes opened the scoring after just 13 minutes before Antonio Candreva converted a penalty three minutes later. Luis Muriel grabbed a late consolation goal for Udinese.
Torino overcame Sassuolo, another promoted side 2-0, while Parma and Chievo played out a goalless stalemate.