Expect the unexpected at the World Cup. Sometimes, the best games are the ones you wouldn't expect to be. Remember South Korea 2-4 Algeria four years ago? For all we know, Morocco vs. Iran might turn out to be a classic.
Probably not though. Both Morocco and Iran are built on solid defensive records and often win games by the odd goal or two. But something has to give in St. Petersburg if either side wants to stand a chance of progressing to the last 16.
Here are four key battles that could decide a tight encounter.
4. Herve Renard vs. Carlos Queiroz
Success meets experience. Herve Renard (the discount Jaime Lannister pictured above) has won two major international tournaments before, something which no other manager at the tournament can claim. He led Zambia and Ivory Coast to Africa Cup of Nations glory, but this is his first taste of the World Cup.
Carlos Queiroz has been here before, with Portugal in 2010 and Iran in 2014. In seven games he's only overseen one victory - against North Korea - but his experience and knowledge could count for a lot.
Despite their different backgrounds, both managers believe in a strong defensive philosophy but they may have to throw caution to the wind if this one is still goalless in the closing stages. Who will stick to his guns and who will roll the dice?
3. The Defensive Midfield Battle
The battle of the holding midfielders promises to be a decisive clash in this match. Iran's two most experienced players, Ehsan Hajsafi and captain Masoud Shojaei, line up alongside each other in the centre of the park, and their consistency in front of a revolving door defence is a key reason for Iran's solidity.
Morocco prefer to stick to just one defensive midfielder, Karim El Ahmadi. The former Aston Villa man recently made his 50th appearance for the Atlas Lions and he is great at breaking up play and starting counter-attacks.
These players will be particularly important in the later games against Portugal and Spain, when there will be more attacks to break up. But in a game of few chances, launching quick attacks from the back may be the key to breaking the deadlock.
2. Alireza Jahanbakhsh vs. Achraf Hakimi
Stand aside, we have a Champions League winner in our midst. Achraf Hakimi made only two appearances on Real Madrid's road to glory, both against Spurs in the group stages, but he still has that medal to show for it. He'd never started for Morocco this time last year but has now nailed down his spot at right back.
Alireza Jahanbakhsh...good luck with that one, commentators. The AZ Alkmaar right winger is coming into the tournament off the back of a stellar season in which he was the top scorer in the Eredivisie with 21 goals. He could capitalise on the inexperience of his opponent to create chances for himself or for Sardar Azmoun. Speaking of which...
1. Sardar Azmoun vs. Medhi Benatia
This is the real clash of the titans, and even those who are cynical about the fixture might be tempted to tune in to see if the Iranian Messi can live up to his nickname. He won't have faced many better defenders than Morocco's talisman, the Juventus centre back Medhi Benatia.
Azmoun's nickname is well-deserved. He has scored 23 goals in 33 games for Iran, making him the country's fifth-highest scorer of all time at the age of just 23. However, the list of teams he's scored against is not exactly a who's who of international football.
In terms of pure ability, Benatia is easily Morocco's best player. He's faced and stopped the real Lionel Messi in the Champions League, so the prospect of facing the Iranian version won't hold any fear for him. Benatia is a noted philanthropist, but Azmoun can expect few gifts on Friday.