Rooney's stunning overhead kick for Man United against Man City 10 years on

Sir Alex Ferguson described it as the best goal he'd ever witnessed at Old Trafford. Wayne Rooney knew right away he wouldn't score a better one. Micah Richards is still scratching his head even now.

Not only was Rooney's overhead kick against Manchester City - a decade ago today - breath-taking in its audacity and execution, it proved immensely significant in the context of Manchester United's season and for the balance of power in the Premier League.

It became almost a 'poster goal' for England's top-flight as well at a time when United and other Premier League sides crossed swords with Barcelona, Inter Milan and other European giants each season in the Champions League.

When you watch replays of the goal now you notice the craned necks of the crowd, a split-second of 'has he actually done that?' followed by an explosion of joy.

Similar thoughts clearly go through Ferguson's mind as he slowly rises to his feet, appearing to utter what may well be a few expletives and then searching for someone to embrace before repeatedly whacking Anderson, stood in front of him, on the back.

Edwin van der Sar, down the other end, can be seen turning to the Stretford End with his arms aloft, taking in the wild celebrations.

Strip the emotion of the moment away to leave cold mathematical fact, however, and the goal gave United a four-point cushion over Arsenal at the top of the table and put eight between them and City.

It was a position they wouldn't relinquish and a 19th league title wasn't long in arriving. So not only was it a goal for the ages but a damn important one as well.

The fact United would regain the Premier League title, from Chelsea, and also reach the Champions League final, losing 3-1 to Barcelona at Wembley, thanks in considerable part to Rooney was ironic really.

The season had started with the England striker questioning United's ambition, with Ferguson dropping the bombshell in October that Rooney wanted to quit the club.

'We are as bemused as anyone can be, we can't quite understand why he would want to leave,' Ferguson said as it emerged Rooney had turned down a new contract two months earlier.

'I was dumbfounded. Only months before he was saying he was at the greatest club in the world.'

Ferguson's words, carefully chosen, proved a masterstroke. A few days later, Rooney had signed a new five-year contract. Any concerns about United's ambition had seemingly vanished overnight.

But if Rooney had a few doubters to convince, he wasn't really doing it. He didn't score his first goal from open play that season until New Year's Day and United were more reliant on the goals of Dimitar Berbatov and Javier Hernandez to keep them in the title hunt.

Come February and United were top of the table and undefeated in the league. But a week before the Manchester derby, they crashed to a surprise 2-1 defeat at Wolves hours after closest challengers Arsenal had thrown away a four-goal lead to draw at Newcastle.

The derby against 'noisy neighbours' City was always going to prove pivotal. At this point, City, whose transformative Abu Dhabi takeover happened in 2008, hadn't won a piece of silverware but United could feel their breath on the back of their necks.

If Roberto Mancini's City could take all three points, they'd be very much in the title race, especially given United had to travel to Chelsea and Liverpool in back-to-back away games the following month.

Arsene Wenger's Arsenal, who beat Wolves 2-0 that day, were also hoping for a United slip-up.

City were the superior side for the most part. David Silva missed a golden chance just two minutes in, rolling a tame shot wide of Van der Sar's goal after Old Trafford pantomime villain Carlos Tevez set him up.

Yaya Toure was bossing the midfield and United struggled to get going until they made the breakthrough four minutes before half-time.

It was Rooney, labouring mostly in vain as United's sole striker, who dropped deep to win a header against Joleon Lescott, allowing the ageless Ryan Giggs to slip a pass through to Nani, who got beyond Pablo Zabaleta to score past Joe Hart.

City were shocked but Mancini responded by bringing on Shaun Wright-Phillips and Edin Dzeko early in the second-half and they combined in the lead-up to Silva's 65th-minute equaliser.

Not that Silva knew a great deal about it. It was Dzeko's shot that hit him on the back and wrong-footed Van der Sar. City cared little how it went in.

A point would have left United looking vulnerable at the top but with 12 minutes remaining, a hero and saviour emerged.

'I wasn't having the best game. To be honest, I just thought I'll go for it,' Rooney later recalled.

Paul Scholes won the ball 40 yards from City's goal and poked a pass wide to Nani on the right. His cross came in with plenty of whip but it appeared to be curving away from Rooney. In fact, it looked like an straightforward clearing header for Richards behind him.

Rooney had other ideas. Showing incredible athleticism, he turned, arced his back and jumped high into the air. It's been suggested by many it came off Rooney's shin but the contact was clean enough to send the ball beyond Hart, who barely moved.

'To this day, I do not know how Wayne Rooney did it,' Richards recalled recently. 'I was preparing to head a ball away from danger. I had my eye on the cross, my neck muscles were tense and everything was set.

'Suddenly, Wayne began to turn and arc his back. Next thing he's up off the ground, his feet are in the air and he makes sublime contact. The ball flies into the net, United win the derby.'

Vincent Kompany had the next-closest view. 'I couldn't believe it because, in that game, I absolutely had him in my pocket. Then he pulls the overhead kick and I'm thinking: 'Oh, come on!'

That goal at that moment in that place instantly restored the eroded bonds of trust and affection between Rooney and the United fans after his contract dispute and a relatively poor season.

With a cheeky grin, Rooney claimed he hadn't scored a better goal since ones in the playground at De La Salle School in Liverpool.

'As soon as I hit it, I knew it was in and it's definitely the best goal I've scored,' Rooney said on that night's Match of the Day. 'It was a special feeling. The fans deserve that from me because I've not had the best of seasons.'

Ferguson, United's manager for 15 years at that point, had seen some memorable goals at Old Trafford but that seemed to rank above them all in his mind.

'It was stunning. Unbelievable. We've had some fantastic goals here but in terms of execution, you'll never see that.'

The true significance of the goal would only later emerge. It kept United clear of the chasing pack and they stayed top despite losing to both Chelsea and Liverpool.

A 1-1 draw at Blackburn Rovers on May 14 secured the title - United's fourth in five seasons and the penultimate one of the Ferguson era.

Rooney's strike partner Berbatov summed up the magnitude of the moment well.

'I can say straight away that was the one United goal I would have liked to have scored,' he said.

'What a great goal, what unbelievable technique, in a derby against one of our biggest rivals who were also going for the Premier League title with us.

'It was an important goal, coming quite late in the game, it was at Old Trafford and really it just had all the conditions for the perfect goal.'