Russia's Achilles heel, Hierro's Spain and VAR ... what we learned!
A VAR decision is seen on the big LCD screen in Volgograd Arena (Getty Images)
Russia - Spain finished top of Group B on Monday despite being held by Morocco while Portugal took second place after a controversial draw with Iran.
Uruguay and Russia were both already through to the knock-out stages but the South Americans clinched top spot in Group A after beating the hosts 3-0.
RUSSIA CRASH BACK DOWN TO EARTH
Russia were dealt a reality check by Uruguay and perhaps it will prove a timely one given they performed so brilliantly on the back of no expectation at the start of this tournament.
In the last 16, Spain will provide at least as tough a test as Uruguay, whose victory was perhaps a little flattering but, still, entirely comfortable.
Many will conclude Russia rode the wave of enthusiasm to beat two poor opponents but were found wanting against a better one and it will be up to them to prove that theory wrong when they return to their favoured Luzhniki Stadium on Sunday.
Uruguay, meanwhile, have hardly set the world alight but they go through top with nine points out of nine. Portugal, their next opponents, will not have it easy.
VAR AT ITS WORST
Portugal scored one of the finest goals of the competition so far, a bending strike from the outside of Ricardo Quaresma's right foot, and Iran equalised late on to seal a dramatic 1-1 draw.
But in between, this was a contest spoiled by a combination of a referee misusing the video assistant referee and players constantly begging for it.
Paraguayan official Enrique Caceres reversed his initial decision and awarded Portugal a penalty that was not clear. He took too long to decide Cristiano Ronaldo did not deserve a red card for throwing an arm. And then he wrongly gave Iran a penalty for a handball by Cedric Soares.
Through it all, the players and managers were wagging fingers and drawing imaginary television screens, with the actual football all-but forgotten. There has been enough in Russia to suggest VAR can be a success but in this game, its flaws were painfully exposed.
GOOD FOR HIERRO, bad for Spain's backline
Spain's problems would seem to lie less with their coach Fernando Hierro, whose substitutions aided a late comeback against Morocco, than their defence, whose mistakes twice gave their opponents the lead.
Hierro, the last-minute replacement for Julen Lopetegui, was brave enough to bring off Diego Costa and David Silva for Iago Aspas and Rodrigo in Kaliningrad. Both were involved in the equaliser, which Aspas flicked home for a 2-2 draw.
Their problems, however, are not at the top end of the field but the back, where Khalid Boutaib scored after a mix-up between Sergio Ramos and Andres Iniesta, before Youssef En-Nesyri headed in from a corner.
Spain had the finesse to make amends but tougher opposition are unlikely to be so generous.