Portugal coach Fernando Santos believes his side "were never quite right" in defence on Tuesday as Sweden came from two goals down to win 3-2 in Funchal.
The match was billed as Cristiano Ronaldo's homecoming, as the Real Madrid star returned to the town where he grew up and represented his country there for the first time.
Ronaldo rather fittingly scored the opening goal as well, before Sweden captain Andreas Granqvist put past his own goalkeeper to make it 2-0.
But Sweden battled back after the break thanks to a Viktor Claesson brace and Joao Cancelo's own goal with the last meaningful kick of the game rounded off a dire second-half performance.
"In the first half we were reasonably good," he told TVI24. "But in defensive terms we were never quite right.
"We created chances, we scored twice, the game was well controlled – but we lost the match. There was little responsibility in the second half.
"I knew what I expected from the team. I make the selections I make, but the second half there was very little responsibility considering what this team is, a team which defends and attacks well."