Riccardo Calafiori was amongst the goalscorers on his first start for Roma.
“It was important to get back to winning ways and a good performance," Fonseca told Sky Sport Italia.
“It was also important to get first place. I want my team to always have courage on the ball, something we usually do, but we didn't against Napoli. That was an off day, that's all.
“I felt all the players wanted to participate today and I had full trust in all of them."
On Calafiori, he added: “I really liked his performance, he is improving and more ready for this stage now. We made a lot of changes and it's important for a coach to feel he has many options to call upon."