Iceland defender Ragnar Sigurdsson says that England underestimated his side and could have lost Monday's round-of-16 game by a bigger score.
Sigurdsson, 30, was named man of the match after an excellent display in the heart of defence during Iceland's stunning 2-1 win over England in Nice on Monday.
And the scorer of Iceland's equaliser believes that England went into the game with the wrong attitude.
"It's important to say it -- the English thought it was going to be an easy match," Sigurdsson said. "But we really have confidence in ourselves.
"I dreamed of taking on England a few years ago. I'm happy that my wish has come true and above all to have beaten them."
France will start as favourites to win Sunday's quarterfinal at the Stade de France, but Sigurdsson has called on Iceland to raise their game once more.
"They're a good team who are quite like England," the Krasnodar central defender said. "France have not played their best football for the moment.
"The quarterfinal could be like tonight's match.
"We'll have to be a bit more dominant and more effective in attack -- we should have beaten the English by a bigger score."