Luis Aragones felt Spain were fortunate to claim their 4-1 triumph over Russia in the opening Group D match of Euro 2008.
"It looks as if this was an easy win but it wasn't like that," said Aragones.
"Physically they are a very strong side and they pressed us hard in the first half. I thought we were a bit lucky.
"We scored on the break and just when they were putting us under heavy pressure we got the second. However, we are very good at playing the ball around when we have control and I'm very happy with the whole group.
"This win will help us psychologically. A 4-1 win gives us a big boost and it is a win that will not just help us but is also good with a view to our next opponents because they are going to look at us with more respect.
"We must not carried away, however, as we have a game against a difficult Sweden side."