The victory extended their Premier League lead over Manchester City, who lost to Sunderland, to seven points.
"Never mind where we are in the table - that was a championship performance," said a delighted Ferguson.
"We dropped two points at Swansea [on Sunday] but made up for it today."
The Scot added: "I think it's given us all a lift - some of the football we played was fantastic."
Robin van Persie has scored six and assisted with three goals in his last eight Premier League games against the Magpies Newcastle have lost four Premier League games 4-3, only Blackburn (five) have lost more games by that scoreline Manchester United have won 16 and lost only one of their last 18 Premier League games at Old Trafford Newcastle took the lead early in the first half when James Perch capitalised on David De Gea's failure to hold Demba Ba's shot.Jonny Evans equalised before the Northern Ireland defender put the ball into his own net.
The goal was initially disallowed after it appeared that assistant referee Jake Collin had judged Magpies striker Papiss Cisse - who was standing behind Evans - to have got the final touch from an offside position.
But after consulting with the linesman, referee Mike Dean allowed the goal to stand, noting that Evans had got the final touch and that Cisse was "non-active".
Ferguson was visibly upset by the decision and remonstrated with Dean, the fourth official and then Collin shortly before the restart.
"The referee changed the linesman's mind," said the Scot.
"He said it was an own goal. But if you see it again, and the referee can't, the guy is in an offside position, then he pulls Evans's arm.
Pardew laments 'unlucky' Newcastle"If that is not interfering, what is? I think it was a bad decision."
Patrice Evra's leveller calmed Ferguson's fury before Papiss Cisse restored Newcastle's lead.
United's top scorer this season, Robin van Persie, grabbed his 16th of the campaign when he followed up his own blocked shot.
And in the final minute of normal time, Javier Hernandez, in the side for the injured Wayne Rooney, took advantage of a lapse in concentration to slide home the winner.
"I wish it was the last game of the season," said Ferguson. "It tells you about the courage of our team though.
"We had a lot of bad decisions against us in the first half."That could have demoralised the team. But they didn't give in. That is the great quality they have.
"As I always say about December, it is a month that tells you everything. Hopefully when we come to 1 January, after that game at Wigan, we are still top of the league."
The result left Alan Pardew's Newcastle side five points above the drop-zone, with a trip to Arsenal next on their fixture list.
"It's difficult, because we've scored three goals here at Old Trafford," said the Magpies boss.
"You think when you score three, you're going to win the game. We hit the bar [Sylvain Marveaux] and the post [Sammy Ameobi] and we scored three goals. But we conceded four.
"We gifted them the last goal and that's been the story for us this season. The last couple of goals were poor for us.
"You always learn something when you play and the players gave a good account of themselves."
Pardew was also critical of the challenge in stoppage time by Antonio Valencia on his Dutch midfielder Vurnon Anita, who was taken off on a stretcher as a result.
"I was a bit upset with that tackle," he added.
"I have seen it again and I don't think it was malicious but Valencia has mistimed it badly and unfortunately it might cost us a player.
"I am not sure what is wrong. It is too early to say."
