#2 The Barcelona players dropped off in the second half
As already indicated, Barcelona started on the front foot and fashioned the best chances of the game early on. At the midway point, all seemed well and good and the Catalans seemed set for a fifth consecutive victory at the home of their biggest rivals.
Quite what Zidane said to his wards at half-time might never be known but the Real Madrid players smelt blood and came all out for the kill at the restart of the game.
Playing out from the back is an integral part of Barcelona's game but Real Madrid's higher defensive line in the second half ensured that multiple players charged at Ter Stegen and his defenders, limiting their passing options and forced them into several errors.
The visitors seemed shell-shocked by this buccaneering display and were not able to perform at their usual levels, with the result being that we witnessed the uncharacteristic sight of Barcelona misplacing several passes in quick succession.
For all the quality within the ranks of the Blaugrana, they should not have been so rattled by the Real Madrid players and the fact that they put up a no-show in the second half was criminal and played a key role in their capitulation at the Bernabeu.