Danny Welbeck netted a late winner for the Red Devils after Robin van Persie had cancelled out Antonio Valencia's header.
"We had an amazing amount of chances," Ferguson told Sky Sports News. "It's always a difficult place to come to but it was a bit disappointing [that we didn't score more].
"We should have rammed home the advantage in the first half."
However, the Scot was pleased with his side's overall performance.
"We have had to play well today and for most of the game we did play well," he added.
United are now three points behind league leaders Manchester City after their 3-2 win over Tottenham Hotspur earlier in the day.