Berbatov had given United a deserved half-time lead with a simple header from a Ryan Giggs cross and the Bulgarian scored a wonderful overhead kick to double the advantage just before the hour mark.
However, Jonny Evans gave away a penalty for a stupid challenge on Fernando Torres which Steven Gerrard coolly converted on 64 and John O'Shea gave away a needless free-kick for a cynical tug on Torres six minutes later.
Gerrard slotted away that too to leave United reeling but Berbatov spared their blushes six minutes from time with a fine header from O'Shea's centre.
It was fully deserved on the balance of play but Sir Alex Ferguson's men can still count themselves extremely fortunate after tossing away a two-goal advantage for the second weekend running.
Berbatov will receive the most heartfelt of congratulations from Evans and O'Shea, who would surely have received the famous hairdryer treatment had it not been for the striker's intervention.
Ferguson is not the only one in these parts who still feel this is the biggest fixture of the Premier League calendar.
Chelsea, Arsenal and even Blackburn may have won the title since Liverpool last did so in 1990. But with their 18 league championships and five European Cups, they remain the most successful English side, even if United have now joined them on the domestic front.
The atmosphere was crackling at kick-off, although the early action failed to match it.
United did create one excellent opportunity, which Nani wasted when he fired wide after Wayne Rooney's shot had bounced kindly for him after striking Gerrard.
But the game was low on incident until Berbatov broke the deadlock by nodding home Ryan Giggs' corner at the near-post.
TV replays did not show Fernando Torres in a good light.
His performance at Birmingham last week was branded "diabolical" by TV pundit and former Liverpool skipper Jamie Redknapp and the Spain striker was again struggling to make an impact.
New United captain Nemanja Vidic, who has suffered more than most at the feet of a man who remains one of the world's best strikers, tidied up one opportunity that had come Torres' way via a fortunate bounce off World Cup final referee Howard Webb.
Torres also trundled a disappointing shot way off target after managing to get a quarter of a yard in front of Vidic as the pair turned on the edge of the area.
All this was forgivable. Just allowing Berbatov, who had already got in front of the former Atletico Madrid star as Giggs strode up to take the corner, just to stoop for it unchallenged, would not have impressed Roy Hodgson very much.
If defensive questions needed to be asked about that, there was nothing more to do than simply admire Berbatov's brilliance when he doubled his side's lead just before the hour.
It was almost impossible to believe it took just two touches to get Nani's right-wing cross into the net.
But it was precisely that. The first to control with his knee. The second to dispatch an overhead kick which left Pepe Reina rooted to the spot as it bounced in off the crossbar.
In any normal season, the contest would have been over.
However, there is a fallibility about United just now that clearly refuses to rectify itself no matter how harsh Ferguson's words.
The rashness with which Evans lunged in on Torres as the striker checked back inside the box gave lie to the theory United can operate effectively without Rio Ferdinand, overlooked for the captaincy and missing with a virus.
On the second occasion, O'Shea could count himself mightily relieved Webb did not reach for the red card once he decided, presumably, that the ball would have reached Edwin van der Sar even without his tug on the edge of the box.
With both situations though, Gerrard found the corner of United's goal with precision, racing gleefully to the ecstatic visiting fans the second time around to hail a position he could not have expected his team would be in 10 minutes previously.
It looked like United had blown it but Berbatov had other ideas and rose to meet O'Shea cross with a fine header that two of his team-mates in particular celebrated with gusto.