For three-quarters of this match, Middlesbrough had thwarted the champions. Ross Turnbull excelled in goal, making a fine save from Wayne Rooney, while Boro's defenders threw themselves into a series of blocks and tackles. The task of breaking down so many black-and-blue-striped shirts was at least useful practice for when Inter Milan come calling in the Champions League, but it was an exercise in frustration for 68 minutes yesterday.
Rooney worked hard, trying to prise open Boro's defence. Cristiano Ronaldo was below-par, distracted by a feud with Emanuel Pogatetz which threatened to boil over at half-time. Carlos Tevez was back in Argentina, granted compassionate leave by Sir Alex Ferguson for an unspecified family issue. So United urgently needed a touch of class from their £30 million summer signing.
Many United fans have yet to be fully convinced by Berbatov, perhaps because he plays the game at his own pace. So languid, so what? When it counted, the Bulgarian found the mark, carrying United to within seven points of leaders Liverpool with two games in hand.
Never mind the quality of the game, feel the quantity of the points. That was the feeling engendered by Berbatov's goal. His finish was laced with trademark finesse, a moment of calm amidst the usual storm of a Premier League match.
The move was begun by Park Ji-sung's back-heel to Michael Carrick, who turned and crossed into the box. For once, Boro's reaction was poor, David Wheater's soft clearance falling to Berbatov, who volleyed neatly past Turnbull.
'It was a great finish,'' enthused Ferguson. 'He has that composure. Dimitar is a marvellous player. He has taken the goal very well and it was a crucial moment.''
For the vanquished manager, Gareth Southgate clearly has work to do. Turnbull and Stewart Downing impressed for Boro but Southgate urgently needs his expensive centre-forward, Afonso Alves, to show a greater relish for the physical fray.
If the Brazilian does not start punching his weight, Boro's sudden slide down the table will continue into the relegation zone. Note to Alves: Berbatov showed that graceful strikers can survive amidst the flying feet of Premier League penalty areas.
Berbatov's deft strike drew sighs of relief from United supporters, who had begun the evening in buoyant mood. Never the home of the humble, Old Trafford had rocked to the announcer's raucous greeting to 'the champions of England, the champions of Europe and the champions of THE WORLD''.
Making their first home appearance since returning in triumph from the Club World Cup in Tokyo, United were royally received by their supporters. The Stretford End, always keen on a dig at Liverpool, had even made a new banner – 'European Capital of Trophies: Manchester 08''.
United's all-conquering team were also awarded the compliment of the visitors' conservative 4-5-1 approach. Flooding midfield in an attempt to drown out United's creativity, Boro used only Alves in attack, although Tuncay and the right-sided Jeremie Aliadiere sought to give the unimpressive Brazilian support from the flanks. Alves' pace briefly troubled United's centre-halves, Nemanja Vidic and the excellent Jonny Evans, as the game opened up but possession predominantly remained in United's domain.
Tuncay and Aliadiere were soon having to drop back to the full-back area as Ronaldo started to make good ground down the flanks, occasionally switching with Park.
Determined to use their games in hand over leaders Liverpool productively, United kept building towards Turnbull's area. Boro's young keeper has been in confident form this season, and he needed to be alert. Ronaldo, having shot wide, then tested Turnbull with a shot that the keeper dealt well with.
The work-rate of Southgate's players was hugely impressive. When Rooney and Ronaldo combined to set up Carrick, Wheater threw himself into the path of the England midfielder's shot. Another vital block came in from Chris Riggott to thwart Berbatov.
United saved their best attack of the first half to last, Ronaldo flicking on a long ball to Rooney, whose first-time left-footed drive was brilliantly parried away by Turnbull. From the ensuing corner, Ronaldo was convinced that Pogatetz had pulled him over, although Martin Atkinson, one of English football's better referees, saw nothing.
'It seemed as though Pogatetz grabbed him around the neck,'' said Ferguson, 'but that happens in penalty boxes all the time. We've had referees coming to meet the players a couple of years ago and they said it would be stamped out with one warning and then a red card. But nothing ever happens.''
Ronaldo continued his complaint as the players jogged off at the break, the European Footballer of the Year airing his grievance to the Boro captain. Matters briefly turned ugly when Pogatetz pushed his forehead dangerously close to Ronaldo's.
The dispute intensified in the tunnel. 'I heard a lot of noise and finger-pointing but I don't think there was anything in it,'' said Southgate. 'The referee and his assistants seemed pretty comfortable with it and they were in the tunnel. When teams are defending from corners, there will be contact.''
Ronaldo and Boro have previous, following allegations of diving against the United No 7, particularly on visits to the Riverside. Boro fans have clearly not forgotten, taunting him with cries of 'that boy Ronaldo – he's off to Madrid''.
United themselves have issues with Pogatetz, guilty of what Ferguson described last night as a 'terrible tackle'' on Rodrigo Possebon in a Carling Cup tie earlier this season. Ferguson stressed that he respected Southgate for apologising, saying he hoped the 'rift'' between the clubs can end.
The temperature remained high for a while. Atkinson had a quiet word with Pogatetz at the break, but Ronaldo was hardly in forgiving mood and clattered the left-back shortly after the resumption of hostilities. But the real damage to Boro was done by Berbatov.