Lionel Messi had a second-half penalty saved as 2014 runners-up Argentina were held by World Cup debutants Iceland.
The five-time Ballon d’Or winner was denied by Hannes Halldorsson after Hordur Magnusson fouled Sergio Aguero.
Aguero had scored his first ever World Cup goal to put two-time winners Argentina ahead on 19 minutes.
However an unfazed Iceland, the smallest nation to qualify for a World Cup finals, equalised just four minutes later through Alfred Finnbogason.