Cristiano Ronaldo's first hat-trick for Manchester United sent them to the Premier League summit as they destroyed managerless Newcastle at Old Trafford.
Cristiano Ronaldo celebrates his hat-trick against Newcastle
The winger's free-kick broke the deadlock after 49 minutes and Carlos Tevez quickly tapped in a second.
Ronaldo capped a stunning four-man move for the third and Rio Ferdinand volleyed in a fourth after 85 minutes.
He sealed his treble via a deflection, and Newcastle's Alan Smith saw red for dissent after Tevez's disputed sixth.
Newcastle's fans, stunned by Harry Redknapp's refusal to succeed sacked Sam Allardyce, paraded banners calling for the appointment of Alan Shearer.
But the Tyneside legend is unlikely to have been tempted towards the hot-seat by what was on offer from a wretched Newcastle side, who conceded all six goals in the second half.
New England coach Fabio Capello was in attendance as Wayne Rooney drove an early chance over the top as Sir Alex Ferguson's side set the platform for first-half domination.
It is a reality check of exactly where we are at - there is loads to do at this football club
Nigel Pearson, Newcastle caretaker
Newcastle keeper Shay Given twice saved well from Rooney as Manchester United threatened to lay siege to the visitors' goal.
Claudio Cacapa then cleared a goal-bound header from John O'Shea before the game had a moment of controversy after 28 minutes.
Ronaldo was furious - as was a gesticulating Sir Alex Ferguson - when referee Rob Styles turned down penalty appeals after he tumbled under challenge from Steven Taylor.
Old Trafford was in a fury, but Ronaldo was looking for the spot-kick and went to ground far too easily.
Michael Owen had the ball in the net for Newcastle as he raced clear, and even though it was ruled out for offside, replays suggested the strike should have been allowed.
As the interval approached, Given saved superbly low from Ronaldo, and it needed a brave clearance from Stephen Carr to block Ryan Giggs as he closed in on the rebound.
The second period opening in dramatic fashion, with Taylor clearing off the line twice within seconds from Tevez and Rooney.
Rooney had numerous chances to heap further misery on Newcastle
But the Old Trafford side were not to be denied and went ahead after 49 minutes, inevitably through Ronaldo.
Newcastle were unhappy when Smith was punished for a foul on Ronaldo - and even more aggrieved when he struck a 20-yard free-kick underneath a jumping defensive wall, via Given's hand.
And the Red Devils doubled their lead eight minutes later after a defensive calamity from Newcastle.
Cacapa played Jose Enrique into trouble in the area, and when he passed to Given, he lashed his clearance against Cacapa. The ball fell for Giggs, who crossed for Tevez to score with ease.
Newcastle were beaten, but Charles N'Zogbia forced a fine save out of Edwin van der Sar with a rising 25-yard drive.
Ronaldo rounded off a four-man move of the highest quality as United added a third after 69 minutes.
Michael Carrick started the passage of play, before Tevez and Rooney combined to play Ronaldo in for an emphatic finish.
The home team were threatening every time they went forward, Given saving well from substitute Danny Simpson and then from Rooney, who was having a personal battle with the Newcastle keeper.
It was embarrassingly one-sided, and Jose Enrique cleared off the line from Carrick, while many players in red appealed for a penalty as Carr clashed with Ferdinand.
Ferdinand stole in at the far post five minutes from time to hammer home Rooney's delicate cross, before Ronaldo claimed his first Premier League treble with a deflected finish.
There was even more agony for Newcastle in injury-time when Tevez added a sixth. Newcastle questioned whether the ball had crossed the line after the Argentine's shot came down off the bar.
Replays showed it was a goal, and former Old Trafford star Smith contested the decision so fiercely he was sent off.
Manchester United manager Sir Alex Ferguson:
"I thought there were too many individuals in the first half. We tried to walk the ball into the net.
"Passing is the key element of our game and once we did that we were fantastic in the second half.
"We relaxed and expressed ourselves. Some of the passing and movement was absolutely outstanding."
Newcastle caretaker boss Nigel Pearson on the managerial situation at St James' Park:
"I am not going to make excuses. It is plain for all to see the situation would be better served by being resolved quickly.
"When you are going through a transition period you need things to be as smooth as possible. Results like this make it very difficult.
"But it is a reality check of exactly where we are at. There is loads to do at this football club."
Man Utd: Van der Sar, O'Shea, Ferdinand, Vidic, Evra (Simpson 67), Ronaldo, Carrick, Anderson (Fletcher 72), Giggs (Nani 72), Rooney, Tevez.
Subs Not Used: Kuszczak, Park.
Goals: Ronaldo 49, Tevez 55, Ronaldo 70, Ferdinand 85, Ronaldo 88, Tevez 90.
Newcastle: Given, Carr, Taylor, Cacapa, Jose Enrique, Milner (Viduka 64), Smith, Butt, N'Zogbia, Duff, Owen (Rozehnal 82).
Subs Not Used: Harper, Emre, LuaLua.
Sent Off: Smith (90).
BBC Sport Player Rater man of the match: Manchester United's Cristiano Ronaldo 8.85 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.