Host nation: Portugal
Even now a year on the shock has yet to fully abate; Greece are the reigning European Champions and therefore, officially at least, the best footballing nation in Europe.
Ahead of the tournament Greece's record in international competition was poor to say the least, in fact their last outing, at the 1994 World Cup, was an unmitigated disaster as they lost all three games, conceding 10 goals and scoring none.
The 2004 Greek vintage comprised honest hardworking players, but no world-beaters and no stars of any great note, while their manager, German Otto Rehhagel, was largely thought by most Greeks to be after one last pay cheque before retiring.
If the Greeks were rank outsiders then by contrast the Portuguese were amongst the very favourites.
The Portuguese had the advantage of being the host nation and, unlike their Greek counterparts, had a side boasting some of European football's most gifted players; from the ageing, yet still supreme Luis Figo, to the exciting youngster Cristiano Ronaldo.
The Portuguese were also coached by the much-vaunted Brazilian Felipe 'Big Phil' Scolari, who amongst other successes, had won South America's Libertadores Cup with two different Brazilian clubs and in 2002 coached Brazil to their fifth World Cup victory.
So, as the two sets of players left the pitch at the Estadio do Drago on June 12 after the opening game it was a shock of seismic proportions that Portugal did so as losers after a 2-1 humbling.
As the tournament progressed pundits and fans were left reeling as they tried to grasp time and again that Greece had somehow managed to traverse the considerable footballing obstacles before them.
Greece's tireless brand of industrious, inventive, predatory football not only spoilt Portugal's opening day party but also claimed the scalp of reigning European Champions France in the quarter-finals and did for the technically gifted Czech Republic (by virtue of silver goal) in the semis.
Ahead of the final there were concerns that the naturally attacking and expressive Portuguese game would be stymied by Greece, who would attempt to suffocate the game.
However, Portugal could only blame themselves for their failure. Deco, Figo and Ronaldo froze, much as they had done on the opening day, and Greece capitalised on their stage fright.
The superb Georgios Seitaridis, Konstantinos Katsouranis, Traianos Dellas and Angelos Charisteas, the man who headed home the final's only goal in the 57th minute, typified the work ethic instilled by Rehhagel, who to his eternal credit managed to create an exceptionally efficient team, far greater than the sum of its technically-limited parts.
However, the considerable achievements of Greece at Euro 2004 should not totally overshadow what was a fascinating tournament graced by many magical moments.
Taking a game from early in the tournament as an example; France 2-1 England would have been a fitting final such was the drama and intrigue of those 90 minutes.
The match was destined to be a classic before kick-off. A palpable rivalry existed between the two sets of fans and particularly between the two sets of players as a result of hostilities carried over from their domestic travails.
It was the game in which Wayne Rooney was unleashed, who, with his fearsome pace, skill and shooting prowess had France on the back-foot from the off. But the game belonged to Zinedine Zidane.
Lampard gave England a 1-0 lead in the 38th minute, while France were ragged and out of sorts. As captain, Zidane had to act. As England waited for the restart Zidane gathered his 10 teammates into a huddle in the middle of the pitch and issued his rallying cry; it was a powerful spectacle and an inspired piece of motivation.
Despite Zidane's best efforts the score remained locked at 1-0 until the game's dying moments and France had surely lost until England pressed the self-destruct button and Zidane exploited two calamities to the full.
After a needlessly conceded foul Zidane despatched a free-kick with seemingly effortless precision. Moments later a loose back-pass resulted in David James upending Thierry Henry for a penalty; again Zidane stepped forward.
While readying himself to take the spot-kick a clearly exhausted Zidane went down on his haunches and threw-up twice. Was it nerves? Had his body refused to accept a huge gulp from a water bottle? Regardless, with his body clearly in turmoil, Zidane summoned the strength to again calmly and clinically despatch a dead-ball in the death throws of the game.
In a game so rich in spectacle Zidane's performance as a leader as much as a player was immense.
The game of the tournament saw the Czech Republic come from two down to reach the last eight by beating Holland 3-2.
Liverpool duo Milan Baros and Vladimir Smicer grabbed the second-half goals that turned the game on its head. Wilfred Bouma and Ruud van Nistelrooy had grabbed early goals to put Holland in command before Czech giant Jan Koller started the fight-back.
The Czechs were left to celebrate in front of their delirious fans while the orange hordes melted away in disbelief.
In a tournament marked out by the achievements of the underdog it would be remiss to leave unmentioned the joy of the Latvians after their triumphant 0-0 draw against the might of Germany.
Competing in their first major tournament, Latvia approached Euro 2004 with a refreshing zeal. Simply reaching Portugal was a triumph for Latvia, the tournament an adventure for the country and for the players who were not burdened by the expectation that weigh down on the leading nations.
Latvia's spirited display in the face of a German side who dominated possession was one of Euro 2004 highlights, not only for the game itself but for the Baltic team's triumphant celebrations at full-time.
And if Rudi Voeller thought 0-0 was bad it could have been so much worse if either of Latvia's two decent penalty claims had been given.
It is largely a moot point whether the relative successes of Latvia and Greece at Euro 2004 were a result of pure endeavour overcoming superior opposition, or an example of increasingly gruelling club schedules impacting on national sides.
The final standings reflect facts, not conjecture. Greece are European champions.