United suffered their third Premier League defeat this season, and have comeback from a losing position in eight out of 10 games, but failed to breach Norwich's tight defence on Saturday.
Chris Hughton has transformed Norwich giving more emphasis to his defence. With a win over Arsenal a month ago and remaining unbeaten in five league matches, Hughton's tactics have worked wonders for his side.
It looked as if United could pull off a thrilling comeback, a win or atleast a draw after Paul Scholes, Danny Welbeck and Anderson came off the bench but Norwich held on to a famous win at home.
Ferguson himself admitted that his side lost to a better team and had earlier warned his defence not to rely on their attack, which eventually failed to deliver.
Wayne Rooney missed the game after failing a late fitness test to an ankle injury but it was down to Norwich's defensive strategy and goalkeeper John Ruddy's impressive saves.
The Canaries restricted United with two walls of four at the back and while the visitors played wide and put in dangerous crosses, the hosts headed clear with ease.
Robin van Persie, United's leading goal-scorer, Javier Hernandez, the super sub who helped United comeback against Aston Villa last time out and Danny Welbeck couldn't help their side keep the top spot.
United have conceded 17 goals already this season, which can be blamed on injuries to key defenders, but having a strong and talented frontline of Van Persie, Welbeck, Hernandez, Ashley Young and Antonio Valencia, the Red Devils had no answers in front of goal.