A moment of madness from Matthijs de Ligt that led to a straight red card robbed the Netherlands of any chance of making the quarterfinals of Euro 2020, with the loss of their defensive lynchpin leaving their team tactics in tatters.
Under pressure from Patrik Schick, De Ligt slipped and flipped the ball back into his path with his left hand to prevent the Czech striker gaining control of it. But referee Sergey Karasev immediately gave a free-kick and a yellow card, which he then upgraded to red after a VAR check.
The loss of De Ligt was immediately felt as the Dutch went from being comfortably in control to being forced onto the back foot by a muscular Czech side that wasn't afraid to be cynical in bringing attacks to a halt.
Often the deepest-lying of Frank de Boer's three centre-backs, De Ligt is the glue that holds the Dutch defence together and allows wing-backs Patrick van Aanholt and Denzel Dumfries to forage far into the opposition half in support of the attack.
The 21-year-old is also key to set pieces for the Dutch both offensively and defensively, and on several occasions in the first half he was targeted with free-kicks and corners by Memphis Depay.
His defensive organisational ability was also sorely missed when Antonin Barak fired a free-kick to the back post for the Czechs and Tomas Kalas headed it back across the goal for Tomas Holes to head home.
Shorn of De Ligt's physical presence at both ends, De Boer shifted to a flat back four, requiring Dumfries to prioritise his defensive duties.
Without their athletic wing backs to support him, Memphis Depay was left to battle against Ondrej Celustka and Tomas Kalas alone when strike partner Donyell Malen was replaced by Quincy Promes.
For all their intricate moves in the first half, the attacking play of the Dutch was too easily read, and the Czechs comfortably dealt with their cut-backs into the centre.
De Boer, who came through the Ajax Amsterdam school of "Total Football" inspired by Johan Cruyff, threw on giant striker Wout Weghorst, who at 1.97m posed a different physical challenge.
But it made little difference after the defence leaked another goal to the Czechs, and the Dutch followed De Ligt towards an early exit from a tournament they had expected much more from.