Quite how it did not end with Ian Holloway's wonderful Blackpool celebrating another famous scalp they will never know. Twice already this season they have beaten Liverpool and, for 45 minutes, it looked certain that Manchester United would be next.
Two goals up at half-time thanks to former Old Trafford defender Craig Cathcart and striker DJ Campbell, Blackpool deserved to be even further ahead after a quite wretched first-half display from the Barclays Premier League leaders.
It could have got even worse had referee Peter Walton not looked so leniently on Rafael's clumsy challenge on Varney in the penalty box early in the second half.
Comeback kings: Dimitar Berbatov fires his second of the game to seal a famous victory
But there is a reason why United are now unbeaten in 28 games. After punching themselves out in the first half, Blackpool spent the second on the ropes as Sir Alex Ferguson's side got up off the floor in dramatic fashion.
Two goals in quick succession from Dimitar Berbatov and substitute Javier Hernandez silenced Bloomfield Road before Berbatov snatched an 88th-minute winner to put the visitors five points clear of Arsenal at the top of the table.
The comeback spared Fergie the ignominy of a repeat of United's defeat by Burnley last season, when they were shocked by top-flight newcomers.
At times in the first half last nightUnited were simply outclassed, in particular by Charlie Adam. The Scotland midfielder responded to a challenge from Holloway to dazzle Liverpool into raising their £4million offer for him with an inspired display.
Precision finish: After pouncing on Ryan Giggs' through ball, Javier Hernandez beat the onrushing Richard Kingson to level matters
Adam pulled all the strings before half-time and his corner kicks led to both Blackpool goals. No wonder Ferguson claimed afterwards that the Scot's set-pieces alone are worth £10m.
'We were deep in the mire,' admitted Fergie. 'We were all over the place. I wonder if the players were a bit over-confident before the game and got a rude awakening. But this club never gives in history tells you that.'
Blackpool could do with the money from Adam. The first meeting between these two clubs in eluded Wayne Rooney by a couple of inches and invited a Blackpool player to reach forglory.
Cathcart was that man, storming in front of Darren Fletcher to head emphatically beyond Edwin van der Sar from close range for his first goal since leaving Old Trafford for £350,000 last summer.
In-form: Dimitar Berbatov (second right) connects with Darren Fletcher's centre to hit his fourth goal in two games
MATCH FACTS BLACKPOOL(4-3-3): Kingson 5; Eardley 6, Evatt 6, Cathcart 7, Baptiste 7; Vaughan 7, Adam 8, Grandin 7;Taylor-Fletcher 6 (Harewood 74min, 5), Campbell 7, Varney 7 (Phillips 68, 5). Subs not used: Rachubka, Southern, Ormerod, Sylvestre, Edwards. Booked: Adam.
MANCHESTER UNITED (4-3-3): Van der Sar 6; Rafael 5 (Anderson 81), Smalling 6, Vidic 5, Evra 5; Fletcher 5,Scholes 5, Gibson 4 (Giggs 46, 7); Nani 5, Berbatov 7, Rooney 4 (Hernandez 66, 7). Subs not used: Lindegaard, Owen, Fabio, Evans. Booked: Scholes, Gibson.
Man of the match: Charlie Adam.
Referee: Peter Walton 6.
Quite why the United goalkeeper pursued the referee to protest was unclear but the home fans did not care. Bloomfield Road was bouncing and Blackpool were rocking.
Nemanja Vidic almost headed another Adam cross into his own goal and deflected David Vaughan's shot over thebar, but it did not flatter Blackpool in the slightest when they snatched a second goal in the 43rd minute.
Again it came from Adam's corner fromthe right after Van der Sar had tipped away David Vaughan's low effort.This time Darron Gibson inadvertently flicked on for Campbell to head home at the far post.
Manager Holloway reflected on the Varney penalty appeal by saying: 'If that's not a penalty then dearie, dearie me. I think it's a stonewall, but maybe I'm biased.
'We were miles away from Chelsea when we played them, we were miles away from Arsenal, but against United we weren't far off.'
Key change: Wayne Rooney's substitution brought Javier Hernandez into play
United's impotence was best summed up by a nonchalant volley from Berbatov which almost hit the corner flag.
It was no surprise to see Ryan Giggs replace Gibson at half-time, nor to see a different United come out for the second half in search of redemption after Ferguson had his say at the interval.
The visiting boss was still not happywith what he was seeing, however, and ended Rooney's 300th appearance for the club soon after the hour mark by replacing him with Hernandez, much to the delight of the home fans.
No mistake: DJ Campbell is unmarked at the far post to nod Charlie Adam's deflected corner home
The change was almost immediate and, after Kingson saved well from the Mexico striker and Nani, he was finally beaten on 72 minutes.
Nani played Fletcher in behind the Blackpool defence and his low cross was bundled home by Berbatov from close range.
Suddenly it was a different game and United were all square two minutes later, Hernandez racing on to Giggs'sthrough-ball and holding off Ian Evatt before slipping the ball past Kingson.
Thumping: Former Red Devil Craig Cathcart (third right) powers Charlie Adam's corner into United's net
Berbatov completed a remarkable comeback two minutes from the end of normal time as he had acres of space to beat Kingson for his 20th goal of the season.
Amazing stuff. The only shame is that Blackpool have nothing to show for it this morning.
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Explore more:People: Dimitar Berbatov, Charlie Adam, David Vaughan, Alex Ferguson, Darren Fletcher, Ian Holloway, Nemanja Vidic, Ryan Giggs, Wayne Rooney, Edwin Van Der Sar, Nani Places: Liverpool, Scotland, Mexico