Wales manager Chris Coleman called his side's Euro 2016 warm-up defeat to Sweden a "slap in the face".
The Stockholm friendly was Wales' only warm-up game before their Euros opener against Slovakia in Bordeaux on Saturday.
But it turned into a painful exercise as they were completely outplayed at the Friends Arena and suffered a 3-0 defeat.
Emil Forsberg and Mikael Lustig rewarded Sweden's superiority either side of the break before substitute John Guidetti rounded off victory three minutes from time.
"We know we can be better than that," said Coleman after Sweden had outmuscled Wales in all departments.
"We get a bit of success, a bit of expectation, sometimes a little bit of complacency and that can give you a little slap in the face.
"That physical thing, it doesn't matter if you're 5ft 4in or 6ft 4in, it's about your intent.
"We were a little bit naive, which would be my criticism today.
"Normally we do a lot to work on being a bit more streetwise on the pitch, like Sweden were.
"We saw how many times they fouled us on the counter-attack to break it up. There's nothing wrong with that, that's international football.
"We were a bit naive, and we haven't been naive for a long time.
"I'd rather that today than me sitting here next week, complaining about the same problem."
Coleman opted to keep his star man Gareth Bale on the bench for 64 minutes, by which point Wales were 2-0 down and heading for a fourth successive game without a win.
Bale had cramped up during Real Madrid's Champions League final victory last weekend, which was won on a penalty shoot-out after 120 minutes, and Coleman did not want to take any risks with his talisman.
"He didn't need 90 minutes today," said Coleman.
"It's good that he's been back with the team, he got some minutes on the pitch and he's totally focused on next week.
"He's walked off the pitch and he's fine. That's the main thing, they all walked off and they're okay."
Coleman insisted Wales' defeat - their heaviest since a 3-0 home loss to Serbia in September 2013 - would have no bearing on their Euro 2016 campaign.
The game against Slovakia will be Wales' first at a major tournament since the 1958 World Cup.
"We've got six days before Slovakia and I don't want to see any long faces," said Coleman.
"I don't want anyone to be negative.
"You can can sense some nerves, that's normal because we're in unknown territory.
"Our lads will be down for the next 24 to 48 hours because they don't like losing.
"It's up to me and my staff now to make sure we give them some reminders about what they've done and what they're capable of and make sure they're in a positive frame of mind this week.
"It's a big week for us and they need to remember the reasons why they're here.
"We've got to make sure when we arrive at the tournament we're back to where we need to be, and I'm sure that will be the case."
Sweden coach Erik Hamren said he was delighted with his side's first victory in four games, especially coming just eight days before their Euro 2016 opener against the Republic of Ireland.
"It's a good win because Wales are a good team and I think they will do well at Euro 2016," said Hamren.
"Z latan (Ibrahimovic) didn't score today, and that is unusual because he always seems to score.
"But he's i mportant to the team and you saw that in the first goal.
"When we are under pressure and we play the long balls he can keep it."
Source: PA
