1300 BST, Wednesday 20 June, Luzhniki Stadium (Moscow), BBC
Portugal and Morocco's emotions were contrasting after their opening games in Group B.
The former fought back from 3-2 down against a fluid Spain side, thanks largely to a typically domineering Cristiano Ronaldo performance. He scored a hat-trick, thus Spain were left stunned and winless.
Morocco, meanwhile, were beaten narrowly by Iran. The North Africans entered the tournament with a quiet confidence. They had qualified convincingly and, though they were handed a tough group, expected to challenge Portugal for second place.
But this was the worst possible start. A victory against Portugal now, if they are to have any chance of qualification, is essential.
Morocco will be wary of Ronaldo, of course. His record in World Cups, prior to Friday night's game, was modest. However, his confidence is now likely to be at a level unmatched by anyone else at the tournament - or any other mortal being for that matter.
Last Time Out
Portugal 3-3 Spain
It was comfortably the best spectacle of the tournament so far. Ronaldo, unerringly focused and clinical, punished every mistake Spain's backline made. His first came from the spot after he had gone over Nacho's outstretched leg.
His second, and most fortunate, was a speculative effort that squirmed in following an uncharacteristic David de Gea error. And the third was a free kick, aimed to perfection, to level the scores late on.
The game was more about Ronaldo than it was Portugal. Other players receded into the background. Without him, Portugal would likely have been beaten by an impressive Spain team, a team that demonstrated the attacking fluidity and cohesion that has made them the favourites of many.
Read five things we learned from Portugal's draw HERE.
That will be a concern for Fernando Santos, Portugal's coach. A more rounded team performance may be necessary to defeat Morocco.
There were plenty of positives against Spain, though, and the feeling is that this is a stronger Portugal team than the one that won the European Championship in France two years ago.
Morocco 0-1 Iran
In a difficult group, Morocco's meeting with Iran was considered something of a knockout tie. The two outsiders: a victory for one might spell the end for the other. And that could well be the case.
Read five things we learned from Morocco's late defeat HERE.
Morocco now face an uphill task if they are to progress into the knockout stages.
The disappointment in St Petersburg on Friday was palpable. Morocco had underwhelmed against a solid, industrious Iran side, but it seemed they had done enough to earn a draw.
Aziz Bouhaddouz's injury time own goal, though, left them with nothing and the daunting prospect of remaining fixtures against Portugal and Spain.
Portugal are not expected to make any changes from the side that drew against Spain. Santos' preferred 4-4-2 system worked well - with a little help from Ronaldo - so it is unlikely he will see any need to change things around.
Andre Silva might be hoping that he is restored to the team after a frustrating night for Gonçalo Guedes against Spain, but Santos is likely to stick with the Valencia man.
Hervé Renard, despite the disappointment of defeat against Iran, is also unlikely to make wholesale changes.
Nordin Amrabat could miss out after suffering a concussion in the previous game, and his place may be taken by Fenerbahce fullback Nabil Dirar, who was not considered fit in time to play against Iran.
Renard will likely look to tweak things tactically to ensure that Morocco are not stunted by Portugal, as they were against Iran.
Key Battle: Cristiano Ronaldo (Portugal) vs Medhi Benatia (Morocco)
Inevitably, Ronaldo will be the man at the centre of attention again. If he plays as he did against Spain he will add further to his tally - with three in one game he has already scored as many goals as in his previous three World Cups combined.
Morocco, then, will need to ensure he is kept relatively subdued if they are to achieve a positive result.
One of those with that unenviable task will be centre back Medhi Benatia, his country's captain and key player.
He is the most high profile name in the Moroccan squad, having played for European giants Bayern Munich and Juventus, and a strong performance here will be crucial.
Benatia has experience of facing off against Ronaldo in the latter stages of the Champions League, too, so he will not be overawed.
Nor are Morocco a side that tend to leak goals: in qualifying they did not concede. There was, however, no Ronaldo in qualifying.
Portugal: Impressive or fortunate?
Portugal were widely praised for their display against Spain. It was understandable: Santos' side twice led against one of the tournament's favourites and rescued a point late on. There were, though, periods in the second half when Portugal were outclassed.
The game's narrative was centred around the brilliance of Ronaldo, and that overshadowed the noticeable flaws in Portugal's performance.
Defensively, they were vulnerable and, aside from Ronaldo, there was not a great deal of inspiration in attack. Two of Ronaldo's goals came from set pieces - a penalty and a free kick - and the other should have been a routine save for de Gea.
It is difficult to read too much into the first game of a tournament, but it should not be assumed that Portugal will swat aside Morocco.
Is too much expected of Morocco?
There was a sense of hope and quiet expectation when Morocco kicked off their first World Cup for 20 years, but it was quickly dampened by a defeat in the most ignominious fashion.
The Africans were one of about 15 countries labelled 'dark horses' in the buildup; now it looks likely they will exit at the first hurdle.
Perhaps the level of expectation played a part. Certainly, Morocco were expected to beat Iran, but they did not account for the stubbornness and efficacy of Carlos Queiroz's Iran, a side that have not lost a game in competitive football since Brazil 2014 and conceded just twice in qualifying.
This is a difficult group, and qualification for the last 16 may be beyond Morocco.
Prediction: Portugal 2-1 Morocco
Portugal should have enough to edge past a Morocco side still dejected from their late defeat against Iran.
Ronaldo is in imperious form and it would be no surprise if he were to have a significant influence again here.
Morocco's hopes will depend on their ability to remain compact and frustrate Portugal, but their performance against Iran suggested a lack of cutting edge in attack.
Listen to the RealSport football writers discuss Group B in Kremlins in the Basement: RealSport’s daily World Cup podcast.