Goals from Jose Callejon and Dries Mertens gave Napoli success at the San Paolo stadium on Sunday and ended Juve's 22-game unbeaten run in the league.
"We were almost perfect," Benitez said to www.sscnapoli.it. "The key to our victory was holding possession.
"Juventus are having an impressive campaign and it was a game between two teams of very high level. We deserved this win.
"I have to compliment my players because they played a spectacular game. We produced a lot, defended well and gave away little."
The win allowed Napoli to close the gap on second-place Roma to six points with seven games remaining, although Roma have a game in hand.
Napoli have gained some confidence from the victory over Juve, but Benitez says his players must keep their feet on the ground.
"We need to look ahead," he said. "We are in the race to finish second and we will continue to fight for that position until the end.
"In order to achieve aims you need to look ahead and not behind."
Napoli are 17 points adrift of Juve in the standings and are not yet playing to their full potential, according to Benitez.
"The major difference between Juve and us is the squad," he said. "When you have a big squad like Juve do you can take on better all three competitions.
"With time we can improve and try to get closer to being more consistent in terms of performances.
"Against Juve we proved that if we always play with the same concentration then we can beat anyone."
Napoli visit Parma in their next match on Sunday.