Lionel Messi scored his third and fourth goals of the World Cup on Wednesday to give Argentina a 2-1 lead against Nigeria going into halftime of their Group F match.
Messi scored in the third minute, slamming in the rebound after Angel Di Maria's shot bounced off the post. But Nigeria's reply was swift as Ahmed Musa cut in from the left flank and beat Sergio Romero with a curling shot toward the far post.
Messi then curled in a perfect free kick just before the break to restore the lead.
Argentina striker Sergio Aguero was substituted for Ezequiel Lavezzi after picking up an injury.
Argentina only needs a draw to win the group, while Nigeria needs to make sure it doesn't lose to guarantee advancement to the second round.