A last-gasp free-kick from the inspirational Steven Gerrard sealed victory for Liverpool after it seemed a penalty from Gareth Barry was about to cancel out a first-half own goal from Villa defender Martin Laursen.
Torres, signed from Atletico Madrid for £20.2million, looked sharp in partnership with Dirk Kuyt although he spurned one golden first-half chance.
"The movement and understanding was good and he showed the touches and class that I would expect from him.
"Normally players when they arrive need a little time to settle in but the understanding with Kuyt was good from the start.
"I took him off with 20 minutes to go and it was difficult for me to decide which player to change. I just felt it was going to give us some fresh legs at the end of the game."
Benitez added: "People were saying how important it was for us to win the opening game and we have done that. But it is just one game.
"I would not have got carried away had we been beaten and I feel just the same now we have won. It is only the start.
"But I felt we deserved the win and their goalkeeper (Stuart Taylor) was the man of the match.
"Sometimes you have to give credit to your opponents and he was really good and made some great saves.
"It was a pity at the end when we gave the penalty away. But Jamie Carragher's arm moved a little bit so it may have been a correct decision.
"But full credit to us for the way we came back after that to get the three points with a great free-kick from Steven Gerrard."