Head coach Luis Enrique’s decision to start Alvaro Morata over in-form Gerard Moreno proved costly as La Roja frustrated in a goalless draw against Sweden.
Tomas Vaclik emerged as a hero for Czech Republic, making some smart stops to deny the hosts.
Croatia's defeat was their first in their opening group match at a UEFA European Championship.
The Leeds United midfielder was a bright spark in the centre of the pitch, and it was fitting that he assisted Raheem Sterling's lone goal of the evening.
The Euro 2020 encounter between Denmark and Finland saw a medical emergency for Christian Eriksen who collapsed on the field.
Both Wales and Switzerland will have to go back to the drawing board before crucial second Euro 2020 encounters after their 1-1 draw.
In Italy there has been a lot of criticism on Ciro Immobile performances with the national team, high pressure on him to perform at the Euro.
Netherland go into their first major tournament since the 2014 World Cup when they take on Ukraine in the Euro 2020 Group C match on Sunday.
Spain's build-up for Euro 2020 has been marred by the team selection and the coronavirus scare to their skipper Sergio Busquets.
If the Scotland football team are to make Euro 2020 memorable for themselves, they will have to overcome plenty of past demons.