Lorenzo Insigne's first-half brace and Dries Mertens' late sealer at the Stadio Olimpico saw Napoli win the cup for the fifth time with a 3-1 victory over Fiorentina.
Juan Manuel Vargas had given Fiorentina hope and they faced 10 men late on when Gokhan Inler was sent off.
Benitez praised his men for their response as the Spaniard claimed his first trophy since taking over at the club in May last year.
"I think it was a beautiful game. We were in control at the start with 2-0 and it seemed simple, but then Fiorentina got back into it," he told Rai Sport.
"We could've got a third goal earlier, but we also worked well in defence and with 10 men did well as a team with real character.
"I have always said losing wouldn't change anything, but a win would be more positive. The fans saw that the team played 100 per cent and that's important."
Benitez backed Insigne to be selected by Italy for the 2014 FIFA World Cup, as the 22-year-old looks to add to his four international caps.
The former Liverpool, Inter and Chelsea boss said the attacker was capable of breaking games open.
"There is talk of him going to the World Cup and I say without doubt he should go, as he can make the difference in any game," Benitez said.
"We knew that we'd all win together or lose together. I am very satisfied with the performance. Fiorentina are a strong side and we worked hard to beat them."
