This was an extraordinary game, chaos and class writ large. This was a game that had everything: spectacular strikes, horrendous misses and relentless scrutiny of the beauty and blemishes of a star's technique.
One moment Wayne Rooney was tapping home, the next he was slipping up.
One moment Fernando Torres was finishing like Romario, the next like Ronnie Rosenthal. Great game, crazy game.
This was also a day that saw second-placed Manchester City dropping points at Fulham, strengthening United's belief that they will retain their title.
Even in third gear, the champions offered too broad a range of goalscoring options from Chris Smalling's header, Nani's majestic strike and Rooney's close-ranger.
A limp linesman's flag helped with the first two but nobody exploits hesitant defending more brutally than Rooney and Co.
Alarmingly for United's rivals, the history books show that Alex Ferguson's thoroughbreds traditionally lengthen their stride only in January.
Not this year. Not with Rooney, Nani, Ashley Young and Phil Jones in this sort of form.
United have come flying out of the starting gate, racing to their best opening to a league season in 26 years: five games, five wins, 21 goals for, four against.
Chelsea's numbers are far less impressive: 10 points, three wins, eight scored, six conceded.
Even in the frustration of defeat, Chelsea can take heart and invaluable knowledge from events in the second half here, especially in the reaction of their young manager Andre Villas-Boas. The Portuguese coach proved he was a man with a game plan that could serve Chelsea well.
Trailing 3-0 at the interval, Villas-Boas had to be bold. He had no choice, of course. Ignominy loomed. The Stretford End was crowing, revelling in what appeared another stroll down coronation street.
Chelsea's fans kept singing, chanting "we're going to win 4-3", but it was more in hope than expectation.
So Villas-Boas acted, introducing Nicolas Anelka for the anonymous Frank Lampard and successfully revamping the system from 4-3-3 to 4-2-3-1.
Suddenly, there was more belief, more movement, more of a platform for Torres. Chelsea were more open, running more freely, the hand-brake off.
Torres scored within 29 seconds and looked far happier. Even the memory of a remarkable late miss, the ball ending up amongst jubilant home fans after he had confidently rounded David de Gea, cannot mask the reality that this was a greatly improved display by Torres.
At the final whistle, the £50m man shook hands with Jonny Evans, then Michael Carrick and Darren Fletcher before Rooney walked up, embraced Chelsea's No 9 and whispered a few words.
Rooney, too, had suffered deep embarrassment as well as joy in front of goal, his left foot failing to grip the turf as his right bore down into the ball, so scuffing his penalty comically wide.
But Rooney's hug with Torres was not a mutual pitying society; it was a reflection that even the best can make mistakes, that class will eventually out.
For all the local cackling over Torres' aberration, the Spaniard left Old Trafford with more of a swagger in his step. No wonder.
Villas-Boas appears to have designed a system that helps Torres.
Behind him, Anelka was busy on the left, Juan Mata far more influential in the hole, while Daniel Sturridge and eventually Romelu Lukaku worked the right.
Anelka, Sturridge and Lukaku are not natural wide players but they may have to sacrifice elements of their game for the collective good.
Chelsea, who have too often relied on their full-backs for width in recent years, still need some wingers.
Whether this 4-2-3-1 system wins trophies remains to be seen but it can be the only way forward for Chelsea.
Villas-Boas deserves long-term support in his attempt to rejuvenate Chelsea; that second period, and particularly the manager's decisiveness, confirmed Villas-Boas is on the right path.
This was his first league defeat since April 2010 when his Academica side lost to Benfica but Villas-Boas took pride from the performance, and particularly the 21 opportunities created at the citadel of the champions.
Even in the first half, as United rattled in three, Chelsea were hardly poor. As the game opened, Torres ran at United's defence until stopped by Evans' magnificent tackle.
The champions woke up, seizing the lead after eight minutes when Smalling headed in Young's free-kick. Whatever the legitimacy of the visitors' squeals for offside, nothing could justify the lax nature of the marking by Lampard in particular.
Back came Chelsea, Torres and Lampard shooting wide before Ramires was denied by de Gea. The TV cameras momentarily rested on the familiar figure of Peter Schmeichel applauding in the smart seats.
Even when the Dane's old team are not excelling they work so hard to close down opponents and then open them up.
With eight minutes of the half remaining, Evans caught Chelsea out with a long pass to Nani. Evans also caught the linesman out. Nani was fractionally offside but dropped back, collected the ball and glided towards goal. Mata's challenge was too lame. Meireles' attempted interception too late. Petr Cech stood no chance as Nani let fly.
Having put Chelsea's defence in a spin, the winger celebrated in suitably head-over-heels fashion.
There was more. As the game melted towards the interval, Jones embarked on one of those lengthy charges that are making him a cult figure at Old Trafford.
Having exchanged passes with Rooney, Jones kept going, soon receiving a back-heel from Nani. Jones' determination eventually saw the ball rebound from John Terry to Nani and then Rooney, who easily tucked away his ninth of the season.
The future of one Rooney's England colleagues then came under unforgiving focus. In the stock market of footballing fortunes, now's the time to sell any shares in Lampard. Villas-Boas' desire for Chelsea to support Torres more quickly is an issue for the 33-year-old Lampard. Anelka immediately released Torres into the box. The finish was a gem, echoing one of Romario's clinical lifted balls over the 'keeper.
After all the hits, it was time for the misses, for Rooney's failed penalty and a shot against the post. Torres was denied by De Gea before firing over and then skewing that shot wretchedly wide.
There was also time for Ashley Cole to catch Javier Hernandez with a filthy challenge that brought yellow but could have drawn red. Cole survived to clear Dimitar Berbatov's effort off the line.
Great game, crazy game. (© Daily Telegraph, London)