Half-time summary: It was like Croatia and Denmark started their match from where Russian Federation and Spain ended theirs. They've already produced one of the most thrilling games of the World Cup, namely their 3-0 victory over a much-fancied Argentina side, although this match could well prove to be a tighter affair.
2' GOAL! Croatia 0-1 Denmark: Incredible!
The BBC and ITV are splitting World Cup TV coverage here in the United Kingdom, and the Croatia v Denmark clash has gone to ITV. He has also scored 13 and assisted five in his last 16 internationals. Denmark come into the match undefeated in 18 games and could spring a surprise.
Luka Modric, the Real Madrid maestro who pulls the strings at the heart of the Croatia midfield, has been one of the best players so far in Russian Federation and Denmark will have to limit his influence to introduce any of their own.
116' - What a stop.
Spain's shock exit to Russian Federation has completely opened up this side of the World Cup draw. Zanka is shown a yellow card.
Croatia's Mario Mandzukic does not look comfortable and walks out of the pitch.
Extra time ends goal-less as Modric misses the penalty.
105' - Substitution: Denmark's Pione Sisto replaces Martin Braithwaite. British Summer Time, while fans in the United States can catch the live stream at 2 p.m. Ante Rebic 10. Luka Modric (c), 4.
Luka Modric and Ivan Perisic are set to be the only players retaining their place from the Group D win.
91' - First period of extra time begins.
We're back for the second half, will we see as explosive a start as we did in the first?
"It is a stern test for us, but it is high time that this generation hurdles this obstacle which we haven't hurdled since 1998". Denmark have scored the opener within the opening two minutes.
Croatia's Marcelo Brozovic during training.
Nicolai Jorgensen (for Cornelius 66) - 5 - Entered the fray in a like-for-like swap with Cornelius, and provided his side with an equally effective outlet up top.
Given their high profiles, plenty of focus has fallen on how they will get on in Nizhny Novgorod, with their rivalry widely portrayed as being crucial to how Sunday's game will unfold. Lasse Schone in for Andreas Christensen.
First, Mathias Jørgensen turned home in the second minute after Croatia failed to clear a long throw-in from Jonas Knudsen, the defender's shot creeping under Subasic to give Denmark the flawless start. He limps off the field just before halftime.
39 minute: Free-kick to Croatia on the left-flank. The cross, though, sails wide right of the post after Dejan Lovren's header. In goal is Leicester City star Kasper Schmeichel.