The Blues were led to victory by a Fernando Torres double but also conceded a penalty to Bibras Natkho and although they hold a two-goal advantage ahead of the Europa League quarter-final second leg, Benitez wants more.
"I am happy with the scoreline but not 100 per cent happy because we conceded a goal when we were in control of the game," said Benitez, who was pleased with the performance from Torres.
"It was a shame that we were a little relaxed and that we conceded that goal. I think the penalty was harsh.
"I was pleased to see the team winning and I said before that Fernando was training really well, working very hard.
"I am pleased for him and not just for the goal but the contribution for the team and the work-rate.
"We always talk about the strikers and how they have to score goals so confidence is there with Fernando today.
"From the beginning I have not doubted his work-rate, but you could see his touch of the ball was much better after the goal because of the confidence he had."