15:00 BST, Sunday 1st July, Luzhniki Stadium (Moscow, Russia), BBC One
Host nation Russia feature in a World Cup knockout match for the first time since 1986 when they face Spain in the capital on Sunday. The Russians, minus a final game 3-0 loss to Uruguay, were convincing in the group stages, surprising many as they scored eight goals.
After dismantling Saudi Arabia and Egypt, the hosts looked on course to provide a shock by winning all three group games and topping the group, though an early red card scuppered their plans.
Spain's campaign has got off to a mixed start. After a thrilling 3-3 draw with rivals Portugal, the 2010 champions trudged to a 1-0 win over Iran, before a last-minute Iago Aspas goal kept their hopes alive against Morocco.
La Furia Roja's fluidity and efficiency is lacking, and Fernando Hierro will know his players need to improve if they are to make any serious headway in Russia.
Last Time Out
Spain 2-2 Morocco
Spain concluded their Group B campaign with a drama-filled 2-2 draw with Morocco, who were already eliminated.
Khalid Boutaib put Morocco ahead - capitalising on a lack of communication between Sergio Ramos and Andres Iniesta - before Isco hit back five minutes later to draw the Spanish level.
Spain then fell behind once again and appeared on the verge of an exit had Iran gone ahead against Portugal, though Iago Aspas' goal stood after being reviewed. A late Iran penalty in the other fixture put Spain top of the group on five points.
Uruguay 3-0 Russia
The Russians ended their group stage campaign disappointingly after such an impressive start. The hosts weren't allowed out of second gear as Uruguay asserted their authority on the game, though they were down to ten men from the 36th minute after Igor Smolnikov picked up his second yellow card.
Luis Suarez's second goal of the tournament - a clever free-kick - put La Celeste ahead before a Denis Cheryshev own goal doubled the advantage.
Russia were able to regain some semblance of control after the break, but Edinson Cavani then opened his World Cup account in added time as Uruguay coasted to a 3-0 win.
Fernando Hierro has a full-strength side at his disposal, though his strongest XI have failed to click as expected thus far. He could make some changes in search of greater team fluidity.
Andres Iniesta will hope to retain his place after replacing Lucas Vasquez against Morocco, whilst Koke could be reinstated in favour of Thiago Alcantara as Hierro looks to protect a vulnerable back four.
Hierro, moreover, has dismissed rumours suggesting that David de Gea will be dropped in favour of Kepa Arrizabalaga.
Russia will revert to the same XI which brought them success in the opening two fixtures after resting much of the squad for the game against Uruguay.
Denis Cheryshev will hope to refocus on his magnificent start after turning the ball into his own net last time out, whilst Igor Smolnikov is unavailable due to suspension. Aleksandr Golovin and Yury Zhirkov are expected to be recalled.
Key Battle: Sergio Busquets (Spain) vs Aleksandr Golovin (Russia)
The importance of the midfield for both sides shouldn't be underestimated, and nor should Spain take Golovin lightly.
The CSKA midfielder has been instrumental in linking midfield to attack for his side, and much of Russia's attacking play goes through the number 17.
Busquets has been the general in the Spanish midfield for some time, though must police Golovin heavily to prevent his side from coming under pressure.
With other threats in the form of Cheryshev and Dzyuba to worry about, it's important, too, that Koke doesn't leave Busquets too exposed to the break.
Golovin has a goal and two assists to his name so far, and is the hosts' best creative option.
Dzyuba testing the defence
Although the Spanish have scored six goals in three games, they've come unstuck defensively and have shipped five, which is perhaps the most important. Morocco put two past them, whilst Portugal managed three and Russia certainly have the strength to make a similar impact.
The key to that is Artem Dzyuba.
The 29-year-old is enjoying a great World Cup and has two goals to his name, though he's been a presence in more ways than one, using his general physicality to unsettle defences.
Sergio Ramos, Gerard Pique and David de Gea look uncharacteristically vulnerable and it's essential that Russia test them with probing long balls into the box to allow Dzyuba to put them under pressure.
Making the most of Diego Costa
Just as Russia have a troublesome striker, Spain have their own in Diego Costa. A menacing presence, you don't want to get on his bad side. Just ask Pepe and Jose Fonte, two Portuguese defenders he made fools of in Spain's opening 3-3 draw.
La Furia Roja often rely on close quarter passing and the vision of their attacking midfielders to unpick defences, though they have another, different, option in Costa that they're not taking advantage of.
His goal against Portugal, from a Busquets long ball, demonstrated what he's best at - bullying his way into the box and finishing precisely - and it's a tactic worth employing if Plan A fails.
Against Iran, for example, Spain had lots of possession on the left flank, but never put any crosses in for Costa to attack and his presence was often wasted in the box. If all else fails, Hierro must remember what sort of player they have in Costa.
Prediction: Spain 2-0 Russia
The Spanish will enter the knockout rounds with a monkey on their backs that they'd sooner be rid of. Having played short of their potential in the first three matches, they'll know as well as any other side that there are no second chances in knockout football, they must turn their performances around.
Russia's wind will have been knocked out of their sails after the loss to Uruguay, and that may have jarred their momentum enough to throw them off course. The home crowd, though, will be as raucous as usual, though the hosts will need every voice if they are to get past their formidable opponents. 2-0.
Listen to the RealSport football writers discuss all the action from Day 15 of the World Cup in Kremlins in the Basement: RealSport’s daily World Cup podcast.