Argentina coach Jorge Sampaoli defended Lionel Messi after the captain erred from the penalty spot in a difficult World Cup debut for 2014's finalists.
Messi had the chance to restore the lead against Iceland in the second half when Maxi Meza was shoved in the area.
But he was denied by an inspired Hannes Halldorsson, who guessed right and kept his effort out on the way to a 1-1 draw in Moscow.
The Barcelona man cut a frustrated figure at the final whistle, but Sampaoli believes he can bounce back and star for the Albiceleste.
"It was an awkward game because Iceland played in their own half blocking Messi's outlets," the coach told reporters after the game.
"He kept looking and he wanted Argentina to win, whatever the analysis of any performance says. I am happy because I know that Leo's commitment to getting us into the next round is still there."
Argentina dominated possession against Iceland, but found little joy in breaking down a fierce defensive unit after Alfred Finnbogason cancelled out Sergio Aguero's fine opener.
And Sampaoli underlined that the entire team was frustrated at having dropped two points.
"We came out determined to dominate the game. Iceland were well-organised defensively and that stopped us from creating chances," he added.
"We did not manage a quick transition game which could unsettle the opponent. We only did that in the second half. I think the key to the game, because of how Iceland defended, was down the left. But we moved the ball around slowly.
"We lacked more vertical movement and midfielders pushing up, which is what happened in the passage where Meza earned the penalty."