By Karolos Grohmann
BELO HORIZONTE, Brazil, June 21 (Reuters) - Argentina captain Lionel Messi, whose last-gasp goal against Iran sent the South Americans through to the World Cup round of 16 on Saturday, said his team would improve as the tournament progresses and peak at the right time.
The Argentines eked out a wafer-thin 1-0 win over the Asian underdogs thanks to Messi's stoppage time goal, his second of the tournament, to move up to six points in Group F.
They next face Nigeria after beating Bosnia 2-1 in their group opener.
"If we analyse both matches we might say we can play better," man-of-the-match Messi told reporters. "But as we go along in the tournament we will be improving and we will reach our full potential."
"We know we are not playing as well as we are expected," he said.
Argentina are among the favourites to lift the trophy but have so far been unconvincing given the talented squad they possess.
"It was difficult to break down their defence to find space. We need spaces because that's when we are dangerous," said Messi.
He and his partners in attack -- Sergio Aguero, Angel Di Maria and Gonzalo Higuain -- had enough opportunities to score, especially in the first half, but got more and more frustrated as the game dragged on.
"I don't think that they were marking just me. Both me and Di Maria could not create spaces," Messi said.
They once again had to rely on Messi's moment of magic at the end, with the forward curling a beautiful left-foot shot into the top corner, triggering wild celebrations in the stands and on the bench.
"When I saw that I had scored I was very, very happy because we were in stoppage time and we wanted to make sure we go through. Then people started screaming, hugging, smiling. It was wonderful moment," said the four-time world player of the year.
"I think today's victory was really important because now we are confident and we have peace of mind. If we had not won today the game against Nigeria would have been different." (Reporting by Karolos Grohmann, Editing by Nigel Hunt)