Iceland's greatest soccer achievement came more easily than expected as a lacklustre England failed to apply serious pressure, their joint-coach Heimir Hallgrimsson says.
England were expected to dominate possession and wear down Iceland's deep defence. Instead, they were defeated 2-1 - their lone goal an early penalty - and Iceland were able to press them high up the pitch and look more dangerous in attack.
"I didn't think the English put us under so much pressure," Hallgrimsson said.
"We were talking about putting on a central defender but we thought we didn't need to do that because we put the pressure higher up the pitch."
Man-of-the-match Rangar Sigurdsson, who equalised early on and as his confidence grew even attempted a bicycle kick in the second half - a rare sight for a central defender, thought England were unprepared.
"They thought this would be a walk in the park," he said.
"They started very well and with great power but they were shocked by the equaliser and the 2-1 goal. They panicked, though they're a good team. As you know, it's difficult to score goals against Iceland."
Iceland beat the Netherlands home and away in qualifying as the Dutch failed to reach Euro 2016. In the group stages at the finals they have drawn with Cristiano Ronald's Portugal and Hungary and beat Austria, tipped as dark horses before the tournament.
Hallgrimsson said the 2-1 win over the latter, clinched in the final seconds, was more stressful than England.
"It was different from the game against Austria, when we needed to defend a lot in our box. We managed to put the pressure higher, at least."
Next up for Iceland, the smallest country to appear in a major championship, are hosts France on Sunday and then a potential semi-final with either Italy or Germany. But few would now write off another upset.
"We've been improving slowly and, in my opinion ... this was our best game yet but we still haven't shown what we can do," Hallgrimsson said.