Benitez saw Robbie Keane score his first goal for the club and captain Steven Gerrard his 100th, before substitute Danny Koevermans grabbed a late consolation for the visitors at Anfield.
"It was almost the perfect night," said the Reds boss.
"It was a really good game for us with lots of positive things, a solid performance with balance and quality.
"Now we must keep on winning. This is a very good start for us - different maybe from last season when we did not start our group matches that well."
Keane and Gerrard came in for particular praise from the manager.
"I was pleased for Robbie Keane," he added.
"Now he has got his first European goal for us, I hope he will now score his first Premier League goal.
"I know Robbie will score a lot more goals for us in the future, so this was just the first step for him.
"I was pleased also for Steven Gerrard. For a midfielder to score 100 goals is very impressive. He is among the very best offensive midfield players anywhere."