Ferguson is delighted with the impact of RvP since his arrival from Arsenal.
"I reckon here at Manchester United we got our Christmas present early - right at the start of the season in fact, when Robin van Persie arrived at Old Trafford," said the manager in his column for Wednesday's United Review for the fixture with Newcastle.
"I am reluctant to subscribe to the cult of an individual because I firmly believe that the essence of a successful football team depends on team-work, and neither are we a one-man team, but sometimes there really is a situation where you are lucky enough to find the last piece of the jigsaw.
"We did it when we brought Eric Cantona to Old Trafford where he proved to be the right player at the right club at the right time. He became the catalyst and springboard for our surge to success. It doesn't have to be signing someone for a record fee; Eric was in fact a snip at a million.
"Cristiano Ronaldo was not a record buy either but he certainly made a difference as he prospered with us to the extent that he came to be regarded by a lot of people as the world's best player."