The goal itself was unspectacular. What followed was anything but.
For when Francisco Costinha struck for Porto in the last minute at Old Trafford on March 9 2004, he not only dumped Manchester United out of the Champions League, but help change the face of football.
As the goal hit the net, Jose Mourinho sprinted and slid down the Old Trafford touchline, catapulting himself into the eye of the football world.
Old Trafford had seen celebrations before. It had seen Alex Ferguson and Brian Kidd on the pitch in 1993. It had seen Arsenal celebrate the title win at Old Trafford in 2002. But nothing like this.
It was audacious. It was arrogant. It was attention seeking. It was Mourinho.
As a result of that game the Portuguese became a big deal. His unfancied Porto side had knocked out European giants Manchester United in their own back yard.
Not only that but they would go on to win the Champions League that season, thrusting Mourinho up to the top table of the European game.
He was then named Chelsea manager of course and has won league titles with The Blues, Inter and Real Madrid and also claimed another Champions League with Inter.
Had that game at Old Trafford gone differently, Mourinho may never have become the iconic manager he is today.
It could have easily gone differently. United were 1-0 up in that second leg tie, which would send them through on away goals, and Paul Scholes thought he had doubled the lead – but was denied by the linesman.
Replays proved Scholes was clearly onside and in all probability had the linesman made the right call, United would have won that game and knocked Mourinho’s Porto out.
Would Mourinho have been made Chelsea manager? Would the football world ever have really known the name Mourinho?
That is impossible to say, but when the Portuguese danced down the Old Trafford turf, he made the world take notice.
He has done the same ever since. Mourinho is bold, brash, bullish.
At times he resembles a bulldog in Armani.
On arrival at Chelsea he created his own fanfare, saying in his first press conference: “I think I am a special one.”
That tag has stuck with him over the years and he has managed to justify it, consistently achieving success on the pitch in three different countries since his Porto days.
Mourinho’s words are arguably his greatest weapon. They surround him like a mist and make him nigh on impossible to pin down or get on top of.
He manages to create a bubble around him and his players that seems impenetrable and instils an ‘us against the world’ mentality at his clubs.
It makes him unpopular. Hated by Italian and Spanish media for his outlandish comments and outrageous behaviour, Mourinho returned to England where the media are a little more in love with ‘the special one’.
The British people have bought into Mourinho the myth. He is an enigma and we hang on his every word.
He has made football management look easy at times, though his increasingly grey hair would say differently, and in his first spell at Chelsea it was.
Manchester United had a side in transition while Arsenal were also in decline. Chelsea spent fortunes under Roman Abramovich and that gave Mourinho everything he needed to stroll to back-to-back Premier League titles in 2005 and 2006.
When United were ready to challenge again, they took back the Premier League title and things went sour for Mourinho.
Sacked by Chelsea he would go on to great things with Inter Milan, winning the treble in 2010 before moving to Real Madrid where he dethroned the imperious Barcelona as league champions.
Trouble has also followed Mourinho around in the last decade and at times he seems to go out of his way to find it.
Touchline bans, eye gouging and spats with managers are just a few things that have blotted the copybook of the Portuguese and is one of the reasons why United are said to have overlooked him as a candidate to replace Ferguson.
Manchester has been intrinsically linked to Mourinho’s timeline over the last ten years, with both United in particular presenting a challenge.
Mourinho has faced United 18 times in his managerial career, losing just twice, and is one of the few managers to have the better of Ferguson in their head-to-head record.
Chelsea won the Premier League in 2006 with a thumping 3-0 over United at Stamford Bridge and Mourinho has lost just once to the Red Devils in the league.
At Inter, United came calling again and knocked Mourinho out of the competition in 2009, before last year Mourinho’s Real Madrid dumped United out after a controversial red card for Nani in the second leg.
Wherever Mourinho has gone, Manchester has never been far away, challenging him ever since that infamous meeting in 2004.
That late Costinha goal set the stepping-stone for Mourinho to claim his position as arguably the most famous and feared manager in the world.
Had Scholes’ goal stood, Mourinho may never have achieved what he has.
Football history is decided upon such small events and the Portuguese has claimed his place in history.
The European landscape has changed beyond all recognition thanks to Jose Mourinho – and it all started ten years ago at Old Trafford.
Image/video courtesy of Chelsea TV/BBC via YouTube, with thanks.