After falling behind to a close-range header from Paul Scholes on seven minutes, the Canaries rallied and forced David de Gea into a string of fine saves. The United keeper was finally beaten seven minutes from time by Norwich skipper Grant Holt before Giggs struck to keep United on the tails of Barclays Premier League leaders Manchester City.
"I have to say we were lucky today, in the sense Norwich had more promise about them. I thought we were lethargic, too casual on the ball. Then when we lost the goal, we played brilliantly," Ferguson said on MUTV. "That tells you something about the temperament, they do not get nervous and started to up their game, so that augers well for us."
Ferguson, who confirmed duo Wayne Rooney and Tom Cleverley have been ruled out of England's friendly against Holland on Wednesday through illness and injury, added: "I think the players were probably a bit embarrassed with the chances they missed, they know they should have done better during the game, and that is irrespective of Norwich being the better team.
"They just kept crossing that ball into the box. Without Rio Ferdinand, Jonny Evans and (David) De Gea, we would have been down. They were brilliant the three of them.
"Norwich deserved a point today and it was a great goal they scored, but at that moment you saw us as Manchester United.
"I am sure this result will have an impact [on the season]. Everyone knows we never give in, no matter who plays us, they know they will have to play right to the death."
Ferguson had recalled his regulars following their midweek defeat by Ajax in the Europa League, looking to close back up on leaders City, although England striker Rooney missed out because of a virus and midfielder Cleverley reportedly struggling with a recurrence of his recent ankle injury.
Giggs, 38, admitted it was a "real honour" to mark his 900th game with the winner.
"It doesn't get any better," the Welshman told BBC Sport. "Norwich put up a great fight but we didn't really play very well. We started the game really well, scored and took our foot off the pedal and Norwich caused us a lot of problems. But I think if you look at the last 10 minutes, we probably just deserved it."
Source: PA
Source: PA