Portugal's talent-packed squad came to the World Cup as one of the favourites but they will now have a fight on their hands just to reach the second round after a shock 3-2 defeat to rank outsiders the United States.
Players had made clear during the long wait for Portugal's first game on Wednesday that they expected tough opposition.
But their porous defence looked unprepared for a fast and disciplined, if not stylish, U.S. side which grabbed their first 3-0 lead in a World Cup finals match since 1930.
In Group D, the only winners have been the two teams which started as underdogs on paper - the USA and co-hosts South Korea - and Portugal have no option but to win their next two matches, against Poland on June 10 and South Korea on June 14.
Even with two wins, Portugal may still have to count points nervously and watch goal the differences of their group rivals up till the final whistle in the Poland-USA game on June 14.
"Regarding the two remaining teams, the fact that one of them has already had a win means we have to win both games," FIFA World Player of the Year Luis Figo said.
Portugal have shown that they can take on the world's best when they are on form, as in the 2000 European championships, when they forced eventual winners France into extra time in the semi-finals and lost only to a controversial penalty.
But in Suwon on Wednesday, Portugal lacked the confidence they famously displayed in their opening tie against England in Euro2000, when they came back from a two-goal deficit in the first 20 minutes to end the game with a convincing 3-2 win.
Figo and Rui Costa were able to orchestrate the England game, with Figo scoring Portugal's first goal and Rui Costa setting up Joao Pinto for a meaty equalising header.
But on Wednesday, Rui Costa looked as if he was still struggling to find form after an injury-ridden season, with many passes going wide. Figo's explosive dribbles were absent, although he set up a goal for Beto Severo with a well-placed corner.
In defence, captain Fernando Couto was less than imposing and the team as a whole gave away possession too often to a faster U.S. side.
Figo said the problem was not fitness or a lack of control of the game or possession. "I think our problem was to have committed basic mistakes which gave the result to the United States," he added.
Couto agreed. "Against England, we were 2-0 down but we played very well. Yesterday we were losing 3-0 and playing very badly. That's the difference," he said after training on Thursday.
Portugal have played some indifferent warm-ups since finishing top of group 2 in the World Cup qualifiers late last year, after a brilliant run of games in which they beat a skilled Netherlands side both home and away.
Although they fought Brazil and Spain to respectable draws, their only win was against World Cup newcomers China in Macao on May 25, and an injury-hit side lost 4-0 to Finland at home in March.
For veterans, like Figo and Rui Costa, members of the "golden boys" side which won world youth championships in 1989 and 1991, this World Cup is likely to be their last chance to shine as they are now around 30.
Before the U.S. match, forward Nuno Gomes said: "We know we are favourites, but we have to prove it on the field."
That will be vital when Portugal line up against Poland on June 10.
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