Lionel Messi had a penalty saved as Argentina were held to a 1-1 draw by Iceland in their World Cup opener.
Messi's chance came and went after 63 minutes when keeper Hannes Halldorsson guessed right to parry the spot-kick and earn a hard-fought point.
The Barcelona star had created the game's first moment of danger when, with six minutes gone, his free kick bounced off a defender and span wide.
A couple of minutes later, Argentina came closer when Nicolas Tagliafico sent in a flicked header that curled just past the far post.
But the best chance of the opening minutes fell to Iceland when a shot from outside the area after nine minutes took a deflection and fell to Birkir Bjarnason, who scuffed wide with just keeper Willy Caballero to beat.
Messi, struggling to find space as Iceland closed him down relentlessly, created a bit of room after 17 minutes but his whipped shot from outside the area was beaten away by Halldorsson.
Argentina, though, broke through within two minutes of that as Sergio Aguero scored his first-ever World Cup goal, getting away from a defender as the ball broke to him and lashing a shot high into the net.
Messi tried his luck from outside the area soon afterwards, his curling strike held by Halldorsson -- but, out of the blue, Iceland were level after 23 minutes, Alfreo Finnbogason stabbing home amid defensive chaos. Gylfi Sigurdsson produced the initial cross, which deflected and eluded Caballero before falling to Finnbogason, who struck from close range.
Nicolas Otamendi looped a header straight at the keeper as Argentina tried to respond, with Lucas Biglia then shooting over from long range.
Sigurdsson had a low shot saved by Caballero as an entertaining first half came towards a conclusion, and the same player blasted a half-volley well wide.
Argentina's Angel Di Maria created the first threat of the second half, winning a corner after a run down the left, but Otamendi steered his header well over.
Back came Iceland, Bjarnason's cross from the left just evading Finnbogason, and Argentina made an early switch when Biglia was replaced by Ever Banega.
Aguero was crowded out as he tried to get a strike in from the right of the area, and the Manchester City striker saw another attempt cannon to safety soon afterwards.
Messi found Banega on the edge of the area as the hour approached, but his shot was blocked by Ragnar Sigurdsson and Messi's follow-up cross was hammered clear.
Argentina then had their penalty when Aguero was barged to the ground by Hordur Magnusson -- but Halldorsson guessed right to save Messi's strike.
Rurik Gislason came on for the injured Johann Berg Gudmundsson in an enforced Iceland change, and Messi curled a free kick over as he tried to make amends for his failure to score from the spot.
Aguero shot straight at Magnusson before, with 15 minutes to go, Argentina brought off Di Maria and replaced him with Cristian Pavon and Iceland switched Gunnarsson for Ari Freyr Skulason.
Almost immediately, Pavon appeared to be clipped inside the area -- but the referee waved play on, and no VAR review was forthcoming.
Nine minutes from the end, Messi curled a superb strike narrowly wide from the edge of the D, and Argentina threw Gonzalo Higuain into the fray as they pressed for a late winner.
Halldorsson made another good stop to claw away Pavon's dangerous cross and Iceland replaced goal scorer Finnbogason with Bjorn Sigurdarson and they held on despite Messi firing narrowly over in stoppage time.