Iran coach Carlos Queiroz laid the blame for his team's 1-0 loss to Argentina squarely on the shoulders of the referee Milorad Mazic after the game.
Near the start of the second half, Argentina's Pablo Zabaleta mistimed a tackle and took down Iran's Ashkan Dejagah in the penalty box, but Mazic let play continue despite protests from Dejagah.
"I'm proud and a little bit frustrated with the result. I hoped it would be different, but what can we do?" said Queiroz. "I have no complaints or excuses, only the frustration with a referee that nobody can understand in the world. How could he not give a clear penalty in front of 40 million people watching the game? It is very sad."
Iran's defence frustrated Argentina for much of the game, while their attack generated a number of legitimate chances in the second half. Dejagah had a header deflected over the crossbar by Sergio Romero at 67 minutes that was Iran's best opportunity up to that point.
"The team played well. We defended very good. We tried to make it hard for Argentina and with a little bit of luck we could have won this game or a draw," said Dejagah.
Before Messi's game-winning goal in injury time, Iran's Reza Ghoochannejhad had a breakaway chance on a through ball that Argentina goalkeeper Sergio Romero deflected away. Minutes later, Messi worked the ball to his left at the top of Iran's penalty box and buried a shot to give Argentina a 1-0 victory.
"When Messi scored it felt terrible," said Dejagah. "But this is what the best players do. They change games in one second."
Now Iran will try to move on. A point against Argentina would have positioned them well to advance from Group F, but the team's hopes are still alive after an opening-round draw with Nigeria.
"The most important thing now is to refresh and focus on the game," said Queiroz. "We need to forget what happened here. We can still go through."
Nigeria faces Bosnia-Herzegovina in their final match on June 25. They'll need a win and some help from Argentina to advance. A full list of possible Group F outcomes is listed here.