His amazing attack came after the game with Swansea, leaving the whole nation wondering if Williams had gone about the Dutch international with a chainsaw!
Sir Alex Ferguson: "I reckon we got our Christmas present early - right at the start of the season when Robin van Persie arrived at Old Trafford.
"I am reluctant to subscribe to the cult of the individual but sometimes there really is a situation when you are lucky enough to find the last piece of the jigsaw.
"As we approach the halfway point of the season, I have no hesitation saying that he has made a vital difference to our chances of making our mark in this season's title race.
"It is quite remarkable how quickly he has settled at Old Trafford.
"He is the consummate professional. He has a good lifestyle with a great sense of responsibility.
"There is no doubt that he has moved us forward as a team."