Morocco had by far the better of the chances before Aziz Bouhaddouz's own goal handed victory to Iran.
2018 World Cup
0-1
Match Events
18' How could Morocco NOT score?
In the middle of a crowded box, Belhanda and Benatia both see strikes blocked by some frenzied defending to keep Morocco from finding the back of the net six yards out.
30' CHANCE! Harit's shot saved
Harit cuts a path down the left channel with considerable ease, and nips into the Iran box before putting a low shot straight to Beiranvand.
44' Azmoun misses a golden 1-on-1 chance!
Azmoun breezes through a loose Moroccan back four and comes up one-on-one with the keeper who gets a hand to his close-range shot 10 yards out; Jahanbakhsh wastes the follow-up and puts it wide off the outside of his boot.
95' OWN GOAL! Morocco 0-1 Iran (A. Bouhaddouz)
It's a horrific own goal from Aziz Bouhaddouz as he goes to head Ehsan Haji Safi's free-kick wide at the near post, only to steer it into his own net!
Disaster for Morocco and jubilation for Iran as their players tear away in celebration and form a pile near the corner post. Iran are ahead with a minute left.
Match Report
Aziz Bouhaddouz scored a calamitous own goal deep into second-half stoppage time as Morocco slipped to a 1-0 defeat to Iran in their first World Cup match for 20 years.
The late drama sparked wild celebrations from the Iran bench in St Petersburg as Carlos Queiroz's side took three points from a game in which they were second best for long periods.
Herve Renard's well-organised team extended Morocco's record of never having won their opening game in the tournament despite dominating the match and carving out opportunities to score either side of half-time.
Iran's counter-attacking strategy had failed to bear fruit with Karim Ansarifard and Sardar Azmoun squandering great chances until their wastefulness was rendered irrelevant by Bouhaddouz's late error.
The Morocco striker, on as a substitute in the 77th minute, put Ehsan Haji Safi's free-kick through his own net with a diving header in the 95th minute of the game, leaving no time for a comeback.
While Iran celebrated, Morocco faced up to the daunting reality of going into their remaining Group B games against Spain and Portugal with no points on the board.
Line-ups
Morocco XI: El Kajoui, Benatia (C), Saiss, Achraf, Harit, Belhanda, Boussoufa, El Ahmadi, Ziyach, N. Amrabat, El Kaabi
Subs: Da Costa, Dirar, Carcela-González, Bouhaddouz, Fajr, Bono, Boutaïb, S. Amrabat, Tagnaouti, Aït Bennasser, Mendyl, En-Nesyri
Iran XI: Beiranvand, Hajisafi, Cheshmi, Pouraliganji, Rezaeian, Shojaei (C), Ebrahimi, Amiri, Ansarifard, Jahanbakhsh, Azmoun
Subs: Dejagah, Ghoochannejhad, Montazeri, Taremi, Mazaheri, Ghoddos, Abedzadeh, Khanzadeh, Torabi, Hosseini, Mohammadi