United romped to an easy 2-0 win at QPR to overhaul Manchester City for four hours before their rivals won 1-0 against Arsenal.
Champions United had been playing catch-up since drawing at Liverpool in mid-October and found themselves five points behind the following week after being humiliated 6-1 in the Manchester derby at Old Trafford.
But despite crashing out of both the Champions League and Carling Cup recently, United have taken 19 Premier League points from 21 to prove they are not prepared to give up their title without a fight.
Asked about the significance of going top for a few hours, manager Ferguson said: "The important thing is to be there on New Year's Day.
"If you're involved right at the top part then you know the second half of the season, we'll relish that."
United have the ideal opportunity to take maximum points over the Christmas period, with games against Fulham, Wigan and Blackburn to come before their first match of 2012 at Newcastle.
Ferguson applauded his side for refusing to "sit and moan" about their shock Champions League demise, although he accused them of wastefulness in a game they could easily have won 6-0.
"If you said before the game, 'Would you take 2-0?', of course we would," he said.
"But on the evidence of today, we should've scored a lot of goals.
"Queens Park Rangers in their home games have been a real problem to a lot of teams.
"But we kept them quiet for most of the game and we played some terrific football at times, and I'm pleased with that."
He added: "We're used to situations like that where we miss chances.
"Quite a few games, we've won 1-0 and said, 'We should have scored more'.
"You know they've got the concentration at the back to deal with that.
"Nonetheless, you want to get that goal that matters and when Michael Carrick scored a second goal, I think that put it to bed."
Ferguson expressed mock anger about Carrick's 30-yard run and finish which gave the midfielder his first Premier League goal for almost two years.
"He's supposed to sit in the middle of the pitch - I maybe have to fine him," he said.
"But he's bang on form, Michael - he's been terrific in the last few weeks and I'm really pleased."
United missed a hatful of chances before that to add to Wayne Rooney's opener, which silenced Loftus Road after just 52 seconds.
Ferguson said: "It was a great start. Away from home, if you get a start like that, it's always a bonus."