What is it?
Croatia have already qualified, but the final match of this group at World Cup 2018 will be pivotal for Iceland who still have an outside chance of qualifying too. If Argentina and Nigeria draw, and Iceland beat Croatia by three clear goals, they'll pull off one of the shocks of the tournament to qualify over Nigeria and Argentina.
When is it?
Today! Tuesday, June 26.
What time is kick-off?
7pm BST.
What TV channel is it on?
BBC 4.
Where is the game being played?
Rostov Arena, Rostov-on-Don.
What is the team news?
Croatia's coach Zlatko Dalic will rest no less than six first team players, who are all at risk of suspension should they pick up a yellow, including Barcelona's Ivan Rakitic.
The decision will no doubt give Iceland a boost, despite only managing one win in six World Cup qualifying fixtures against them. They may be missing centre-back Ragnar Sigurdsson, who went off with a head-injury in their loss to Nigeria.
What's the latest news on the two teams?
Iceland's Rúrik Gíslason has new-found fame since his team's debut on football's biggest stage. His Instagram following sky-rocketed, increasing from 30,000 at the beginning of the tournament to one million at the last count.
Meanwhile Croatia defender Dejan Lovren has said that his Croatia teammate Luka Modric is overlooked as one of the best players in the world.
"Modric would probably be getting more attention than he is right now if he was a German or Spanish player," he said.
"He would maybe even be a Ballon d’Or winner. Because we are a smaller country, he does get less attention than he deserves."
What are the odds?
Iceland to win 5/2
Croatia to win 5/4
Draw 12/5
What's our prediction?
Iceland will have more of a chance because of Croatia resting key players, but the three clear goal difference needed for them to progress will leave them too open at the back.
Prediction: Iceland 1 Croatia 3.