Today, Jose Mourinho is rarely out of the headlines. As far as managers go, the Chelsea boss is a blockbuster name.
Yet, during most of his stint in charge of Porto, he was by no means a renowned figure, particularly outside of his native Portugal.
However, all of that changed 11 years ago today when a 41-year-old Mourinho took his side to face Manchester United at Old Trafford in the last 16 of the Champions League.
The visitors held the advantage thanks to Benni McCarthy, who bagged a brace of goals in the opening leg at the Estadio do Dragao to cancel out an early opener from United midfielder Quinton Fortune.
Paul Scholes, though, put United back in command on the away goals rule in the 31st minute of the return meeting when he headed in John O'Shea's cross at the near post.
The midfielder also had the ball in the net again moments before the break, but he was incorrectly ruled to have been offside by the referee's assistant.
It would prove to be a crucial decision, as Mourinho and his Porto players sent shockwaves reverberating around Old Trafford in the final minute.
Phil Neville fouled Edgaras Jankauskas close to the penalty area and from the resultant set-piece situation, McCarthy fired goalwards. United goalkeeper Tim Howard failed to hold the ball and the American's mistake was punished as Costinha fired in the rebound to send the away side through to the quarter-finals 3-2 on aggregate.
As the Porto players ran off to celebrate in front of their travelling supporters by the corner flag, they were joined by their manager, who had sprinted down the touchline to get involved.
It was a moment that propelled Mourinho into the limelight and he went on the guide his unfancied team to Champions League glory that year, before being appointed the manager of Chelsea as a result of his achievements.
MAN UNITED: Howard; P Neville, Brown, O'Shea, G Neville; Fletcher, Djemba-Djemba, Butt, Giggs, Scholes; Van Nistelrooy
PORTO: Baia; Ferreira, Costa, Carvalho, Valente; Alenitchev, Costinha, Maniche, Deco; Alberto, McCarthy