Ciro Immobile jumped from the bench to score twice with Isaksen influential.
He later said, "I am very happy, after we lost against Salernitana we needed to regain confidence and play well in Champions League. The objective now is to make up ground in the championship too, because we are not doing well.
"I would like to always play, I know I have excellent players like Felipe, Pedro and Zaccagni in front of me, but I want to earn my opportunities. Unfortunately Zaccagni had this injury, so today I had more space to help the team win this victory.
"My feeling with Sarri is excellent. I'm learning every day to be able to improve in many aspects of his game and I feel like I'm succeeding."
Isaksen added: "Immobile is very important, every year he is among the best scorers, he is a great player. We all want to help him score, including me."