It was almost a perfect afternoon for Manchester City, if such emotion could be divined from an occasion heavy with the memory of tragedy. Yet by the end, what began as a tribute, a reminiscence of a great team lost, became a testament to the power of football, its capacity to surprise and inspire, to reinvent heroes and special moments.

This was Manchester United’s day, recast by its conclusion as City’s. It was their first league victory at Old Trafford since 1974, sealing their first league double over United since 1969-70. A spoke has been inserted in United’s bid to chase down Arsenal and the damage of this home defeat will only be fully revealed this evening, after Arsenal have played Blackburn Rovers at the Emirates Stadium. Unless Mark Hughes can do his former club a favour, Arsène Wenger’s league leaders will be five points clear.

Psychologically, who can measure what part Manchester City’s supporters played in this victory? Dread surrounded the issue of the silence in memory of the Munich dead before the match, with the fear that it would be defiled by noisy interruptions from the visiting team’s fans. In the event, it passed off beautifully, with not a murmur from the away end, who stood holding blue and white scarves, in sympathy with the red and white of the home team. When Howard Webb, the referee, blew his whistle, City chests were puffed out in pride. Maybe this buoyed the team, too.

Could it be that it even affected United? Did the unity, the shared bond, take an edge from their game, usually so finely honed on derby occasions? Certainly something was missing from United’s performance, which Carlos Queiroz, the assistant manager, predictably put down to midweek friendly internationals, as if City had a team of carthorses, untroubled by such commitments (for the record, the best player on the pitch, Richard Dunne, the City captain, played 90 minutes for Ireland against Brazil, who are believed to be quite good). It was as if United lacked motivation; maybe they were just charmed.

As for City, they did everything right. The respect for the Munich memorial was followed by a lack of respect for United’s status as champions, barring a 4-1-4-1 formation that throttled the home team’s forwards, because of the excellent screening of Dietmar Hamann. Missing Wayne Rooney, United’s attack was limp, a midfield quartet of Nani, Paul Scholes, Anderson and Ryan Giggs, were unable to break through and chances were limited to pot shots from range that Joe Hart, the Manchester City goalkeeper, dealt with in exemplary fashion.

In some ways the match was similar to the corresponding fixture in August, in that all the prime performances came from men in blue shirts. Dunne was the outstanding defender, but Michael Ball, the left back, ran him a close second. Hamann was voted man of the match, but Stephen Ireland’s busy display in the heat of battle was equally impressive. Benjani Mwaruwari, the new signing, was alone up front but proved more than a handful for Rio Ferdinand, who had one of those matches in which his mind appeared to be elsewhere.

Cristiano Ronaldo, too, suffered a serious dip in form, petulant when his tricks and crosses did not work, stomping around, cursing divots in the pitch for his failure to rise to this occasion and establish a link between his greatness and the ghosts of United’s glorious past.

When City took the lead after 25 minutes, it was no fluke, more reward for hard work that had forced Ferdinand to take a cross by Gelson Fernandes off the head of Benjani. It was a case of third time lucky for City, Martin Petrov initially releasing Ireland, whose run was cut off by Edwin van der Sar, the United goalkeeper, the rebound falling to Darius Vassell. His shot was blocked by Van der Sar, frantically recovering his ground, but the ball ran loose to Vassell again and this time he beat all obstacles.

United’s response was underwhelming — a shot by Carlos Tévez kept out by Hart — and the feeling grew that this would be City’s day. Something about United was not right; maybe the emotion of the occasion, maybe the pressure of the chase, maybe tiredness, maybe the absence of Rooney. The four league matches United have lost this season have had a common factor. No Rooney, no points, it would seem.

Petrov came close with a low cross that Van der Sar tipped round with Fernandes closing in after 42 minutes and there followed a succession of corners, at which point City went farther ahead. Petrov took three in total and not one was impressive, before a clearance allowed him to whip in a cross from the right from an altered angle, which caught United unaware.

Benjani had cleverly lost Wes Brown — in United’s defence, the Zimbabwe striker found a group of people who were, amazingly, even dozier than him at Southampton airport — and the ball glanced off his left shoulder, eluding the fingertips of Van der Sar, as City’s fans began to dream.

The paucity of United’s resistance was shocking and their goal, scored by Michael Carrick, a substitute, in the final seconds, was flattering. By the time it went in, much of Old Trafford had emptied, to the derision of the City fans, although at least it spared the home team the indignity of a Munich remembrance that ended in boos (as happened, briefly, at the end of the first half).

Sir Alex Ferguson departed hastily after the match also, to fly to South Africa to promote the 2008-09 pre-season tour — a sign of the times, perhaps — leaving Queiroz to moan, ungraciously, about outside factors when a simple tribute to City’s resilience over two derby matches this season would have sufficed.

Perhaps the most remarkable thing is that on a day when minds were focused on a frozen moment of Manchester’s football history, City stirred evocative memories of a different kind. The Denis Law goal in 1974, for instance, that marked the previous City victory at Old Trafford; or the 1969-70 season, which City began on an equal footing with their neighbours, having won the FA Cup in May and the league title the season before that.

It is unlikely that parity is their future, although in Sven-Göran Eriksson they have a manager who is closer to achieving it than the majority of his predecessors. At the very least he has given the blue part of Manchester bragging rights and that is the last thing that was expected to come out of yesterday’s match, for all sorts of reasons.

How they rated

Manchester United

4-4-2

E van der Sar 6

W Brown 5

R Ferdinand 4

N Vidic 5

J O’Shea Y 5

Nani 5

P Scholes 5

Anderson 5

R Giggs 6

C Tévez 6

C Ronaldo 5

Substitutes: Park Ji Sung 5 (for Nani, 63min), O Hargreaves (for Anderson, 73), M Carrick (for O’Shea, 73) Not used: T Kuszczak, D Simpson. Next: Newcastle (a).

Manchester City .

4-1-4-1

J Hart 8

N Onuoha 7

M Richards 7

R Dunne 9

M Ball 8

D Hamann 8

D Vassell 8

G Fernandes 8

S Ireland 8

M Petrov 8

Benjani 7

Substitutes: F Caicedo (for Benjani, 75min), Sun Jihai (for Hamann, 83), J Garrido (for Petrov, 86) Not used: A Isaksson, Geovanni. Next: Everton (h).

Goalscorers: Manchester United Carrick 90 Manchester City: Vassell 25, Benjani 45

Referee H Webb

Attendance 75,970

Changing times

- The previous time Manchester City won a league match at Old Trafford a pint of beer cost 20p, a loaf of bread 14p and the average price of a house was a touch over £10,000, about equal to Gary Neville’s daily wage.

- It was April 1974 and Denis Law backheeled Manchester United into the second division in a 1-0 win on the last day of the season.

- The Old Trafford legend was mobbed by teammates, but refused to celebrate, wearing an expression so sheepish that it looked as if he had insulted a close family member.

- A crestfallen Law retired from the Football League immediately afterwards. Aptly, the No 1 single that week was Terry Jacks’s Seasons In The Sun.

- As it turned out, even at 0-0 United were doomed to relegation, but Law’s late winner put the final nail in the coffin and sparked crowd trouble. He said of the goal: “I have seldom felt so depressed in my life as I did that weekend.” Words by Marcus Leroux