Sound the Heartwork klaxon, for this is the Strait of Gibraltar derby. These two countries even share land borders thanks to Spain's own colonial past with three sections of Spanish land on the Moroccan coast.
Edit: oh Spain do the stupid thing of a video line-up rather than a picture
How did they get here:
Morocco: Won their qualifying group ahead of Guinea, Guinea-Bissau and Sudan, then a playoff against DR Congo. Won their group, beating Canada and Belgium while drawing with Canada.
Spain: Won their qualifying group containing Greece and Sweden, but only beat Costa Rica before drawing with Germany and losing to Japan.
Last 16 regulars?
Morocco: One previous appearance in 1986, losing to Germany 1-0. This tournament they have already equalled their number of wins across all previous World Cups combined with sparse appearances.
Spain: 8 previous ties, most of which have resulted in victories. Their last one was a penalty loss to Russia, they beat Portugal 1-0 in 2010 and lost 3-1 to France in 2006.
Previous meetings?
Yes! 2-2 in the last 2018 group stage match, with Iago Aspas equalising late on for Spain.
They have even contested a World Cup knockout stage of sorts in a playoff for Chile 62. In the Africa-Europe clashes Spain won matches 3-2 and 1-0 to progress to the finals, Alfredo Di Stefano among the scorers.
Laura Woods hosts coverage of England before the match itself kicks off at 3.