Belgium looked limp, laboured and lacklustre in the first half against Denmark, producing a single shot while facing nine in return as the Copenhagen crowd roared its approval.
After 45 minutes of Kevin De Bruyne, they were transformed: not only did they win the game to progress to the last 16, but they suddenly looked capable of beating anyone they might meet between now and the final on July 11.
It sounds hyperbolic – Belgium, after all, still have just a 9.9 per cent chance of lifting the trophy, according to Stats Perform's predictor model – but De Bruyne's display off the bench was enough to get even the most pessimistic of fans dreaming.
It was so decisive that it secured the midfielder the honour of being the Euro 2020 Player of Matchday Two, as per the Opta index, which gave him a rating of 97.68.
De Bruyne only needed nine minutes to make his first telling contribution at these finals. His assist for Thorgan Hazard's equaliser was exquisite: his two touches, one to control Romelu Lukaku's pass and one to square the ball for his team-mate's tap-in, looked supremely simple and yet took three Denmark defenders out of the game.
It was the eighth assist De Bruyne has provided at major international tournaments since the start of the 2014 World Cup. In that time, only Eden Hazard (nine) has managed more. Perhaps it was fitting that the Real Madrid winger's latest was to tee up De Bruyne's winner here.
A superb, slick passing move that started with Lukaku saw Hazard touch the ball into De Bruyne's path, on the edge of the penalty area. He had space to size up the first-time shot, but this was by no means an easy finish – at least, it wouldn't be for most.
De Bruyne strode onto the ball and, with his weaker left foot, rifled it low past the despairing Kasper Schmeichel. We should probably have seen it coming: he has scored 10 of his past 14 international goals from outside the box. It also ensured Hazard joined De Bruyne as the only European player to assist a goal at each of the past four major international tournaments.
Beyond the obvious positives of overturning Belgium's deficit for a 2-1 win, De Bruyne seemed to have a galvanising effect on Roberto Martinez's team. He completed 20 passes, 14 of which were in Denmark's half; only five Belgium players completed more, and all of them started the contest. He also had more touches (36) than Romelu Lukaku (33), who played the whole game, and he contested more duels (six) than Jason Denayer (five), who spent 90 minutes at the heart of a three-man defence that was far from untroubled.
Put simply, if De Bruyne could do this in his first 45 minutes at Euro 2020, what might he do over Belgium's games still to come? For the rest of the continent, it's a frightening thought.