Belgium finally silenced their critics.
The Europeans, billed as fifth favorites for the event, had won all their three group games but had failed to impress their critics.
The much-fancied side needed extra time to crack heroic United States goalkeeper Tim Howard in a thrilling 2-1 extra-time victory on Tuesday that set up a World Cup quarter-final clash with Argentina.
And if there was any one man responsible for the result, he was Kevin de Bruyne.
The former Chelsea player, who now plies his trade with Vfl Wolfsburg in Germany, scored the opener and created the second for Marc Wilmots' side.
The Belgians had dominated the first 90 minutes but a barrage of efforts were thwarted by an inspired Howard, whose resistance was finally broken in the 93rd minute when midfielder De Bruyne buried an angled shot from seven meters.
In a pulsating extra time, substitute striker Rome Lukaku powered home a second in the 105th minute after a clever De Bruyne pass, before Julian Green's neat volley ensured a tense finish in which Clint Dempsey almost sneaked an equalizer.
"We had about 15 chances, we were controlling the game I think it is largely deserved even though at the end we conceded one," Belgium coach Wilmots told reporters.
"My players reached their limits to qualify. I said fresh legs would be important today and that is how it was. Now the whole of Belgium can celebrate."
The lively De Bruyne should have done better only if Howard had not been in the best of form on the day.
Image: Kevin De Bruyne of Belgium acknowledges the fans after defeating the United States 2-1 in extra time in the Round of 16 at Arena Fonte Nova in Salvador
Photo: Laurence Griffiths/Getty Images