Gonzalo Higuain's eighth-minute strike was enough for Argentina to overcome Belgium in Brasilia and reach the semi-finals of the World Cup this afternoon.
The one and only goal came in the early stages when Higuain accurately volleyed a bouncing ball into the far corner after Angel di Maria's pass deflected kindly his way.
It was the Napoli striker's first goal for his country since August 2013 and the first goal from open play that Belgium had conceded in normal time at the tournament.
Belgium's only real chance in the first half fell to Kevin Mirallas, whose low header from Jan Vertonghen's cross fizzed a yard past the post.
Lionel Messi's best effort of the first half came just before the break when he curled a 19-yard free kick just over the crossbar.
Higuain was inches away from a second 10 minutes after the interval when he nutmegged Vincent Kompany to bear down on goal and shot against the crossbar from 15 yards.
Marouane Fellaini then had a chance to equalise from another Vertonghen cross, but couldn't direct his header on target.
Messi had a glorious chance to kill the game off when he ran clear on the break in added time and was denied by Thibaut Courtois's sprawling save.
Belgium stormed up the other end and had an opening of their own when Romelu Lukaku rolled his man in the area but couldn't pick out a teammate in the middle. The loose ball fell to Axel Witsel, who could only blaze the last shot of the game over the bar.
The winner of tonight's last quarter-final between Netherlands and Costa Rica await Argentina in the semi-final.
The Albiceleste may be without Angel di Maria after he was forced off through injury in the opening half.