Hannes Thor Halldorsson was the hero for Iceland as the goalkeeper's penalty save from Lionel Messi secured his side a sensational 1-1 draw against Argentina.
Messi failed to convert from the spot in the second half of an eventful Group D opener at the Otkrytie Arena in Moscow.
Sergio Aguero had fired the beaten finalists from four years ago ahead in the 19th minute, finally breaking his World Cup fasting at the ninth attempt with a rising left-footed drive
Iceland refused to give in on the main stage, Alfred Finnbogason capitalising on Willy Caballero's weak punch to score his country's first goal in the history of the tournament just four minutes later.