Belgium have now drawn back-to-back matches at this World Cup and face the prospect of a second successive group-stage exit.
But it could have been a very different story had Romelu Lukaku connected with Kevin de Bruyne's inviting cross inside the opening five minutes.
The Napoli striker - his country's all-time leading scorer - was handed his first start since June 2025 and was expected to spearhead Belgium's bid for a much-needed victory, but looked off the pace.
Instead, a string of outstanding saves from Iran goalkeeper Alireza Beiranvand, coupled with a costly red card for Belgium's young defender Nathan Ngoy, condemned the Red Devils to another frustrating night on the international stage.
The result leaves the 2018 semi-finalists in danger of failing to progress from Group G. Belgium will still go through if they beat New Zealand in their final group game, but any other result would leave their progress in doubt.
For Iran, meanwhile - who have only been allowed to fly into the United States a day before each match - the draw means it is the first time they have avoided defeat in their opening two matches of a World Cup.
Over the past decade or so, it was thought it would be a case of when, not if, Belgium would win the World Cup.
After failing to qualify for the 2006 and 2010 finals, the Red Devils returned to the global stage in Brazil in 2014 armed with one of the most exciting generations of talent international football has seen.
In attack, they were blessed with Premier League stars Eden Hazard and Lukaku, while the midfield combined the guile of Mousa Dembele with the elegance and creativity of De Bruyne.
There was quality throughout the defence too, with the likes of Jan Vertonghen, Toby Alderweireld and Vincent Kompany.
It was, therefore, little surprise that expectations were so high. Hazard, Lukaku and De Bruyne were all regarded among the finest players in the Premier League and Belgium appeared destined to become a dominant international force.
That is why, a little over a decade later, there is a tinge of sadness surrounding the current state of the national team after a 'Golden Generation' that never quite fulfilled its promise at major tournaments.
That was a sense of decline embodied by both Lukaku, 33, and De Bruyne, 34, on Sunday as the pair struggled to influence the game against an ill-prepared Iran side.
After the Napoli duo missed a large amount of the season through hamstring injuries, it has begged the question as to whether their sub-par performances at this World Cup so far have been down to a lack of match fitness or if age is finally catching up with them.
"This is the biggest problem for Belgium - their two best players, De Bruyne and Lukaku, are not match-fit," said former France midfielder Patrick Vieira.
"You can see their lack of tempo. Lukaku's first touch and link-up was really poor today. They really need more time. Let's wait and see.
"Belgium didn't impress. I think Iran deserved the point. Even if Belgium created good chances with 10 men, overall it was a disappointing performance."
Former Manchester United and Republic of Ireland midfielder Roy Keane said: "In terms of the quality of the game I thought it was rubbish. Really bad.
"The standard in terms of passing, movement, decision-making - so poor."
Even after a lacklustre performance, De Bruyne - who won six league titles with Manchester City - almost bailed his nation out in the second half when he rolled back the years and plucked the ball out of the sky before crossing for Maxim de Cuyper, who could not convert from close range.
"De Bruyne still created the best moment of the second half, the clear-cut chance," added Keane.
"That is what these brilliant players do, they just need one moment and he certainly produced that. That should have been a defining moment of the game."
Since 2014, Belgium have reached the semi-finals in only one of the six major international tournaments they have featured in.
It is no wonder the feeling of underperforming has become all too familiar for the Red Devils.
Belgium - without winger Jeremy Doku through illness - were left frustrated as they struggled to turn their dominance into goals, despite enjoying the majority of possession and registering 11 shots.
The Red Devils went close through Youri Tielemans, but it was Iran who thought they had opened the scoring in the 25th minute when Mehdi Taremi found the net.
The Olympiacos forward finished off a cleverly worked free-kick routine, only for his effort to be ruled out for offside following a lengthy video review.
It was the fourth consecutive World Cup match in which Belgium had failed to score before half-time.
They started the second half brightly and would have been ahead in the 58th minute had Beiranvand not produced an outstanding save to deny Brighton's De Cuyper after a magnificent touch and cross from De Bruyne.
However, Belgium were unable to find a winning goal despite attempting 23 shots over the course of the 90 minutes.
It is the most shots they have managed in a World Cup match without scoring since 1994.