Napoli overturned a first-half deficit to beat Torino 2-1 at the Stadio San Paolo.
Fabio Quagliarella gave Torino a 14th-minute lead but his effort was cancelled after half-time, with Insigne and Jose Callejon on target.
"The key for me with Insigne is his work-rate," Benitez told Sky Sport Italia of the 23-year-old.
"In football you cannot talk about a player who stands still, as they need to help out in defence and also attack.
"Lorenzo can do that, he just needs to be a little more precise in the finish."
Napoli's rise up the table has helped ease the pressure on Benitez, whose job was reportedly on the line following the club's failure to qualify for the Champions League group stage.
"I wasn't tense recently. I was perplexed by everything that was being said after the season we had last year," he said.
"We know there is a lot of passion in the city, but there are financially stronger clubs and we have to work extra hard to close that gap.
"Was I offended? No, perplexed. A team that notched up a new record of Serie A points, won 10 away games, scored over 100 goals and finished in third place while winning the Coppa Italia achieved a great deal.
"I realise people expect a great deal, but with football it’s all a question of moments. If even one of our chances from previous games had gone in, we would’ve had as many points as last season."
