Javier Hernandez's goal in the 90th minute gave Manchester United a potentially vital 4-3 win over Newcastle United on Wednesday to give them a seven-point Premier League lead.
The Mexican forward slid in to meet Michael Carrick's right-wing cross with two seconds left on the clock to break the hearts of a Newcastle side who had dreamt of a famous win on at least three occasions during a pulsating game.
Jonny Evans scored at each end after James Perch had claimed an early opening goal for Alan Pardew's team, who came to Manchester without an away league victory this season.
Patrice Evra equalised for the home team, as did Robin van Persie, after Papiss Cisse had shot Newcastle into the lead for the third, and final, time.
Substitute Samuel Ameobi might have handed the visitors the lead for a fourth time, hitting the post with an 85th-minute shot.
Manchester United's Scottish manager Alex Ferguson reacts at the final whistle after their 4-3 win during the English Premier League football match between Manchester United and Newcastle United at Old Trafford in Manchester, north-west England on December 26, 2012.
But a breathtaking game may yet come under the scrutiny of the Football Association following the actions of United manager Alex Ferguson as the players waited for the second half to kick off.
The veteran Scot marched onto the pitch to remonstrate with referee Mike Dean, his assistant and fourth official over the decision to award Newcastle's controversial second goal after 28 minutes.
Evans put the ball into his own goal from Danny Simpson's cross and although Cisse was in an offside position, Dean allowed the goal to stand after a long discussion with linesman Jake Collin, who had initially flagged for offside.
Newcastle had taken just four minutes to take the lead, thanks to an error by goalkeeper David de Gea and the defenders in front of him, who allowed Demba Ba too much space on the edge of the area after he had pounced on a poor piece of control from Carrick.
The Newcastle forward sent in a low, hard shot that the goalkeeper kept out, but Perch had the simple task of driving the ball into the gaping net.
With Wayne Rooney and Danny Welbeck absent, through injury and illness respectively, United struggled to carve out a meaningful chance prior to their equaliser on 25 minutes.
Newcastle United's French midfielder Sylvain Marveaux (L) vies with Manchester United's Mexican forward Javier Hernandez (R) during the English Premier League football match between Manchester United and Newcastle United at Old Trafford in Manchester, north-west England on December 26, 2012. United won 4-3.
Van Persie's left-wing free-kick was helped into the area by Ryan Giggs, passing through a mass of bodies before arriving at the feet of Hernandez, whose initial shot was well saved by Tim Krul, but the ball broke for Evans to finish.
Sylvain Marveaux hit the bar for Newcastle with a free-kick just before the break but United's first-half problems persisted, and Ba might have extended the lead when he headed just wide from a Cisse cross.
There had been no sign of the equaliser coming when van Persie pumped in a long 58th-minute ball from the left, but Newcastle failed to clear and Evra planted an impressive 18-yard shot past the dive of Krul.
The lead lasted 10 minutes before Newcastle yet again exposed United's defensive weaknesses.
Former United winger Gabriel Obertan, brought on as a substitute moments earlier, gathered Davide Santon's throw-in, sprinted down the left and picked out Cisse with a pull-back that the striker converted with minimal fuss.
United were well below-par but needed just two minutes to equalise for a third time after a right-wing run by Antonio Valencia ended with him finding van Persie just inside the area.
Krul saved well from the initial shot before Carrick neatly worked the rebound back to the Dutchman, who converted from 15 yards.
That was the catalyst for an extraordinary final 20 minutes in which victory could have gone to either side.
Hernandez rounded Krul but could not produce a shot from a bad angle, while Marveaux tested de Gea from 20 yards and Hernandez appealed for a penalty after his shot hit Fabricio Coloccini.
Van Persie then rolled a shot just wide, Hernandez's diving header flew inches off target, and the Mexican steered an 88th-minute header directly at Krul from a Giggs cross.
Amid all that, Ameobi struck the post, but Hernandez's aim was to prove truer.