It couldn't have been the preparation so it must have been the pressure. Spain went home and Morocco on to their first World Cup quarter-finals after 120 minutes and some yielded no goal. Morocco converted three of their four penalties, the last by Achraf Hakimi who was born in Madrid, to win the shootout 3-0.
Penalties, Spain coach Luis Enrique had said, was about practice, the pressure could be managed. In front of their supporters but with an amphitheatre roaring against them, Spain were denied by the upright and Morocco goalkeeper Yassine Bounou who guessed right for all three shots. Spain goalie Unai Simon saved but could do nothing as Hakimi banged down the middle.
Enrique had hoped Spain supporters, far fewer in number, would be able to "silence" those backing Morocco. There was more chance of snow in these parts than that happening at the box-like sold out Education City Stadium. There were reports of Morocco's national carrier providing extra flights for Tuesday's round-of-16 game and of the north African country's embassy giving 500 tickets to Moroccans living in Qatar.
They could have done all that many times over and still demand would have outstripped supply. This wasn't about two countries separated by the Strait of Gibraltar, which have good relations, Enrique had pointed out. Or about players from both sides groomed by the system in Spain: Hakimi was at Real Madrid and Abde Ezzalzouli is on loan to Osasuna from Barcelona, Bounou and Youssef En-Nesyri play for Sevilla and Munir Mohamamedi was born in Spain.
This was about a team against a region. Whistles, boos and jeers rang out every time Spain had the ball. And given that Enrique had said they would not change their style, it meant nearly all the time. When regulation time ended, Spain had 73% of the ball, played back-heels in front of both goals, but had only half-chances to show.
Morocco, their coach Walid Regragui said, were playing their "fourth final of this World Cup." One in which they were obdurate in their refusal to yield against a team that has won the World Cup and began this edition with a seven-goal win. This was as efficient an exhibition of the middle to low block as any.
Morocco had not conceded in this World Cup barring a self-goal against Canada. They had confidence in their abilities to thwart Spain by keeping their defensive shape and Regragui had convinced the squad that they belonged at this level. The back-header by Abdelhamid Sabiri and the block by Selim Amallah in the same move in the 100th minute were but two examples of what happened from when Hakim Ziyech left a leg on Jordi Alba in the second minute.
It was a show of focus and fortitude typified by Morocco skipper Romain Saiss playing on with a heavily strapped leg and his central defensive partner Nayef Aguerd, who had made an excellent challenge to deny Alvaro Morata in the second half, refusing a stretcher even though he needed support to leave the pitch.
Yes, they also had a slice of luck when Pablo Sarabia's shot skimmed the upright in what was the last move before penalties. The tale could have ended earlier had Morata found the right pass for Ansu Fati and if Nico Williams got a strand of his dreadlocks to a Dani Olmo delivery, both in extra-time.
But when the teams went into the break at extra-time, it was Spain who were breathing a sigh of relief. Walid Cheddira had tried to exploit Spain's high line from when he came on in the 82nd minute but had failed to time his runs. He did in the 104th when Azz-Eddine Ounahi slipped in a ball and Rodri missed his challenge. Cheddira fired but Simon got a leg to deny Morocco. He broke free again in the 115th but couldn't beat Rodri before Laporte brought the situation under control.
So, on to the penalties it was. Sarabia thudded into the post but Bounou had guessed right. As he did for Carlos Soler, both of whom having been brought on for the penalties. And for Busquets. It meant Spain going home and a country from the Arab world finding itself among the world's best eight teams.