Not an impressive result for Spain, who didn't look almost as sharp in attack as they did in the 3-3 draw against Portugal to open the tournament.
It was an attack versus defence exercise as Iran continued to camp deep, and they were making it nearly impossible for Spain to pick their passes in a forward position. However Iran's defence was breached in the 54 minute by Diego Costa with his ninth goal in nine worldwide matches. Despite the result, La Roja were quite impressive throughout much of their clash against Portugal and were only denied an opening day win from a brilliant Cristiano Ronaldo hatrick.
Spain were camped in the Iran half for the most part of the opening 30 minutes, but they struggled to find openings in the final third.
Lucas Vazquez, also at Real, comes in on the right side of midfield in place of Atletico Madrid's Koke to join Isco and David Silva in support of striker Diego Costa, who scored twice against Portugal.
Iran equalized the match in the 64th minute but Saeid Ezatolahi's goal was disallowed after VAR rueled it offside.
Queiroz's troops continued to threaten as the second half went on, with Mehdi Taremi heading over the crossbar at the far post on 81 minutes.
"We can guarantee that we will keep working for our dreams, and our dream is to qualify for the second round".
After watching the match, some have been impressed by Iran's terrific and resilient performance against Hierro's side. For the Iranian players to play against Spain, we are winners because we learnt a lot.
Costa had a bust-up with Beiranvand toward the end of the first half after the Iran keeper went down in the box.
Costa was accused of standing on the foot of Iran's Ali Beiranvand.
Iran coach Carlos Queiroz revealed himself to be a big fan of VAR technology despite the replays having ruled out Ezatolahi's strike because of a marginal offside.
In the final quarter hour Iran battled for a late equaliser, but after Vahid Amiri showed class to nutmeg Pique deep on the left and fire over an inviting cross, Taremi's thundering header flew just over the bar as a relieved De Gea looked on.