But Fernando Torres produced an 83rd minute equaliser with Benitez praising the spirit and character of his players who were able to set up a fourth round replay at Stamford Bridge.
"In the first half we didn't do what we had to do. We knew it would be difficult but we made too many mistakes in our approach and the way we wanted to play," he told the club's official website.
"I was very pleased with the reaction of the players in the second half, we showed quality, character and it was much better.
"They were pushing and we knew it could be difficult, but we kept giving the ball away in simple situations wh
"In the second half we showed our real level, like we did last week against Arsenal. We have no excuses as to why we didn't play well in the first half, we just didn't do the right things.
"Oscar and Fernando scored great goals, and it was because the team were doing well and we were creating things."