The Red Devils were beaten 1-0 by the Blues at Stamford Bridge after Demba Ba volleyed home brilliantly early in the second half and Ferguson feels his players were not in control, especially when they went a goal down.
"We were comfortable in the first half and I couldn't see them getting into the game or being any great threat to us. But the goal, as it always does, changed the game," he said.
"We spoke about Ba and the experience we had with him a couple of years ago at Newcastle when he scored exactly the same type of goal. We were caught napping, to be honest. It wasn't a good start for us right at the beginning of the second half.
"After that I think we lacked the composure to win the game and create proper openings. We had a lot of possession but didn't make the best use of it and they caused us quite a few problems on the counter-attack."