Robin van Persie scored the only goal after just 33 seconds, his 14th of the season, which proved enough to keep the Red Devils ahead of Manchester City at the top of the Premier League. It was not pretty, though, and Carlton Cole could easily have snatched a point in the latter stages.
"We got a great start," said Ferguson.
"You hope to go on from a start like that and some of our football was very good but we never quite finished them off.
"We have played with the diamond quite a few times this season and done very well so I don't think that is an excuse.
"But we have got the three points and are still ahead in the league.
"With Chelsea drawing it draws us away from them a little bit further.
"But of course, (Manchester) City are on our tails so it is going to be a long season."
While not exactly unfortunate, with a little bit more composure West Ham could easily have gained a share of the spoils. But, as Sam Allardyce pointed out, in players like Van Persie, United have extra class.
"Manchester United have lots of players who will have good spells and can come up trumps when they need them to," said Allardyce.
"Robin van Persie is a quality player and we have largely kept him quiet. "But he will score 20 goals for Manchester United, maybe 30. In the end that is normally the difference.
"What chances did Manchester United create? None really. We went right to the very end but couldn't quite make it.
"Whether they played to their potential or not doesn't matter does it? They still won. They have a nasty habit of doing that."