The second pair of last-16 World Cup matches will be played on Sunday when Spain face hosts Russia and Croatia take on Denmark.
Here, Press Association Sport flags up what to look out for.
Will the real Spain stand up?
At times in their opening 3-3 draw with Portugal, Spain were mesmeric – moving the ball in a way Sir Alex Ferguson once described as like being “on a carousel” that makes opponents dizzy. The Barcelona model was there in all its glory with Sergio Busquets, Andres Iniesta, David Silva, Koke and Isco manipulating the ball effortlessly and Diego Costa providing a genuine goal threat in front of them. But subsequent displays against Iran and Morocco have put a question mark against Spain’s bid to repeat their 2010 World Cup triumph.
De Gea in the spotlight
Spain’s inconsistencies have been magnified by the form of Manchester United goalkeeper David de Gea. Manager Fernando Hierro has said De Gea will definitely play against Russia in Moscow, despite being badly short of confidence. De Gea has not looked at ease since his howler gifted Cristiano Ronaldo a goal in Spain’s opening group game. United fans glow in the Twitter hashtag #DaveSaves, but De Gea has already been beaten five times at the World Cup and another poor performance could cost him his place should Spain progress.
James mind games
England’s wait to find out whether Colombia star James Rodriguez will be lining up against them in Moscow on Tuesday looks as if it will continue until the team sheets are handed in. The 2014 World Cup’s Golden Boot winner lasted just half-an-hour of Colombia’s crucial group win against Senegal on Thursday. The Colombian camp continued to give nothing away over Rodriguez’s fitness at a press conference on Saturday, keeping England in the dark as to whether the Bayern Munich loanee will make the last 16 clash.
Can Russia keep their party going?
Russia came into the tournament with low expectations and some bemoaning the team as the poorest in living memory. But handsome wins over Saudi Arabia and Egypt booked a quickfire last-16 spot and raised hopes that Russia could actually achieve something special at their own World Cup. But a convincing 3-0 defeat to Uruguay suggests Russia are unlikely to be a match for Spain. If they do go out, at least the Russians can take satisfaction from putting on a tournament to remember.
Midfield maestros do battle
Croatia’s case as dark horses to win the World Cup is mostly down to the creativity of their two midfield masters, Luka Modric and Ivan Rakitic. The pair are good enough to excel at Real Madrid and Barcelona and can dictate the tempo of a game against the best opposition. Coming up against Denmark pitches them against Christian Eriksen. It will be a fascinating battle as the Tottenham playmaker is also capable of winning a game with a moment of brilliance, particularly from set-piece situations around the penalty area.