Benitez said: "Carra was at right-back so we could use Martin (Skrtel) at centre-back. We had Carra, Martin and Sami (Hyypia) who were good in the air, so we could defend set-pieces better.
"I've seen some games when Carra has been at right-back and I knew he could defend well in that position.
"But I didn't expect to see him up there as a winger crossing so well.
"It was really good to see, great for us and great for him. He wasn't very happy about being asked to play at right-back but he's a professional.
"I think we needed to give something to our supporters and try to make people happy. The players knew that and I think the commitment of all the team was fantastic.
"It was important to get the three points. A lot of times we have been playing well but drawing or losing.
"It was important to win, to show character and the players did that."