Argentina dominated possession but rarely looked like penetrating the massed ranks of defenders and Iran, growing in confidence after the break, were twice denied as headers by Reza Ghoochannejhad and Ashkan Dejagah were saved by Romero, the second a spectacular tip over the bar.
The game looked to be heading for a draw until Messi scored his second of the tournament to put the Group F favourites on six points following their opening win over Bosnia.
Iran and Nigeria have one point while Bosnia are on zero ahead of their game against the Africans in Cuiaba later on Saturday. (Writing by Mitch Phillips, editing by Ossian Shine)
- Sports & Recreation
- Ashkan Dejagah
- Reza Ghoochannejhad