Group B opponents Iran and Portugal will be squaring off against each other for their final World Cup fixture of the group stage at the Mordovia Arena on Monday.
Portugal are currently second in said group, tied on four points with Spain, but the Iranians are still within a shot of qualifying for the knockout round of the tournament and will do so if they can manage a victory over Fernando Santos' side this week.
Having beaten Morocco in their opening match and following up with a loss to Spain in their second, Iran are lodged in the third spot of Group B with three points. A win would take them into the top half, as well as to the round of 16, while condemning Portugal to a third-place finish.
Of course, Santos has the most fearsome player in the tournament playing under him. Cristiano Ronaldo, who has four goals to his name so far, has shown that he can carry Portugal on his back and inspire them to victory. So the Iranians will have quite the task on their hands.
These two sides have only met twice before, with their initial duel kicking off in 1972. They also met in the group stage at the World Cup 12 years ago and guess who was on the scoresheet for Portugal. That's right, an up-and-coming superstar named Ronaldo.
Former Barcelona and Chelsea midfielder Deco opened things up for Seleccao das Quinas in the 62nd minute of the match, rifling a 22-yard screamer past the keeper.
With 12 minutes left to go, Luis Figo was brought down in the Iranian box, Ronaldo stepped up to take the penalty and double Portugal's lead.
It was a game of many chances for the Portuguese, who were indeed dominant and could have scored more. Ronaldo would also have a goal ruled offside in the dying embers, while Iran missed a chance to pull one back in stoppage time after an unmarked Javad Nekounam headed wide as he rose to catch a free-kick.
The victory would seal Portugal's passage to the knockout round, something they're hoping to accomplish again when the teams meet on Monday.
Iran came into the tournament on the back of a remarkable qualifying campaign that saw them top their group without losing a single game. They also won their opening game against Morocco, who are ready to fly home.
Portugal's opener ended in a draw, but it was a remarkable game in which Ronaldo scored a hat-trick. The Real Madrid man also scored the solitary goal in the 1-0 win over the Moroccan side.
The Portuguese captured the European Championship trophy in 2016 and have been in rich form since. They also topped their qualifying group, winning nine matches and only losing once en route to these World Cup finals.
The Iranian side haven't reported any injuries going into their final match of the opening rounds. Carlos Queiroz should name pretty much the same side he did for their match against the Spaniards and will hope they can deliver against Europe's big fish.
Meanwhile, Santos has no new injury concerns ahead of this match either and he isn't expected to ring any changes as he looks to seal passage to the knockout stage.
This will be a huge game for both teams involved and their futures hinge on this result. The Iranian's have shown some grit in this tournament so far, but so have Portugal, who do boast arguably the world's best player.
The Madrid man has a penchant for stepping up and delivering in big games and it is expected that he will do so with his nation's hopes resting on his shoulders. He definitely won't be minding the pressure, and Portugal failing to get the result in this one is surely unthinkable.
Ronaldo will be looking to add to his tally in this match and it would be great if his teammates would pitch in too.
Score Prediction: Iran 1-3 Portugal