Hearts sank like lost shoes in a muddy field in Manchester when the news emerged last week. Derision, resignation, bafflement: United had a perfect opportunity to rid themselves of Marouane Fellaini but instead they gave him a new contract.

If one listened to some of the wailing, it felt as if Fellaini was an irritating house guest, the sort who puts his shoes on the couch and takes bites out of the cheese. The time had come for him to move on but United not only invited him back in for a brew, they made him up a proper bed in the spare room.

And then there is Nacer Chadli. It was, to say the least, an eyebrow‑raiser when he was even named in the Belgium squad for Russia: one had to look up where he was playing his club football and, as it turns out, it was still West Brom. Not that he had actually played much: he had spent virtually the whole season out injured, making his call-up even more baffling. This was not Brazil fretting on Neymar’s fitness: this was Nacer Chadli.

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And yet these two unwanted toys, discarded in the minds of many, were the men who saved Belgium. One could almost hear the snorts when they were introduced, proof that Roberto Martínez was a smooth‑talking snake-oil salesman, not a manager but a motivational speaker with some coaching badges. Fellaini and Chadli? Pah!

Shows what we know. Or, it shows that football generally, and this World Cup specifically, is absolute chaos. Nothing can be predicted. Nothing can be planned for.

This is a tournament where Russia look like potential champions and Germany are sulking at home for the first time since before the war. A tournament where Thomas Müller and Andrés Iniesta have been virtual irrelevances but Fellaini and Chadli are game-changers.

Before the game the talk was about a more conventionally desirable player. On Sunday Eden Hazard was asked about the departure from the tournament of Lionel Messi and Cristiano Ronaldo and what that might mean to him.

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It was framed as creating a vacancy for a tournament-defining star, a chance for Hazard to translate his frequent brilliance for Chelsea on to the international stage. “It’s time to shine,” he said, with a sort of dead-eyed certainty.

He started as if that was his big aim, the juices flowing from the off. There was a driving run through the middle, a delicate flick with his right foot, a finger‑stinging shot with his left. He seemed more aggressive than usual: not in the tackle but in his movements. Fine skill combined with a point to prove.

But as the game progressed he faded. He might take it as an insult that Martínez reached for the hammer and smashed the emergency glass, reaching for the sinewy tree that goes by the name Fellaini. Insult it might be but it worked.

Perhaps, if nothing else, this game might provide some succour to despairing United fans. Really, they should know what Fellaini is there for by now. He is an impact substitute, a creator of chaos to turn to when order and sound planning have not worked.

Assuming he is used in these sorts of circumstance, as the Plan B muscle, he is a perfectly fine option – effective, ugly, not capable of elite football, not capable of much that is recognised as football at all, really, and yet someone who can change matches.

Which is what he did here. Japan almost looked cocky in the minutes after they scored their second through Takashi Inui and then, when Fellaini and Chadli were introduced, it was as if they looked to the sidelines and thought: “Is that all they’ve got? This is in the bag, lads.”

Well, it was not in the bag. It was very much out of the bag. Thanks to Marouane Fellaini and Nacer Chadli, Belgium’s golden generation live to fight another day. What a world.