Subs used: Mohammadi (5), Jahanbakhsh (4), Ghoddos (n/a).
Of course, with all due respect to Morocco, the Group B opener last Friday was - on paper - always going to be Team Melli's best chance of getting three points.
Although the first half bore a striking resemblance to an "attack versus defence" training session, Iran still threatened sporadically.
Silva had the best chance of the opening period on the half-hour mark.
Fernando Hierro, Spain's sporting director, is now at the helm but barely a week into the tournament La Roja - expected to join Brazil, Germany and France in the latter stages - have endured more drama than they would have wanted or expected.
Dani Carvajal returned from a hamstring injury to replace Nacho in the Spain XI, with Lucas Vazquez also coming in for Koke. Remarkably, it was the Iranians who almost broke the deadlock, when Karim Ansarifard fired into the side netting after some seriously unconvincing Spanish defending.
David Silva sent a free kick straight into the arms of keeper Ali Beiranvand in the 25th minute for Spain's first shot on goal.
Some great vision from Iniesta, and a slice of luck, however broke Iranian hearts when Costa spun and latched on to the ball before seeing his shot rebound off Rezaeian and into the net.
Queiroz's side pushed hard for the equaliser and thought they had it when the recalled Saeid Ezatolahi struck from close range in the 63rd minute, latching onto a ball headed down. Moreover, Carlos Queiroz's side conceded just two goals and were unbeaten in their qualifying campaign, so it seemed unlikely that they'd be pushovers - even for a side of Spain's calibre. HEAD TO HEAD:Both sides have not met before, the clash on Wednesday will be first between both sides.
A member of the Iran national team staff was hospitalised Wednesday after the team was denied a goal when video review held up an offside call in their World Cup match against Spain.
They netted a total of eight goals in winning the World Cup in South Africa eight years ago, but they will need to pass the ball quicker and stretch teams more readily if they are to have a chance of emulating their achievements of 2010 in Russian Federation. He attempted one more after his goal, which means he's attempted four overall.
It was Queiroz who gave the news during a press conference after the match. He delivered a number of set-pieces and crosses into the area - with varying degrees of success - and continues to show his importance and quality for Spain.