On March 26, Spain and France will face off in one of the most crucial qualifiers many of their players will ever experience.
With France moving two points clear atop Group I, la Furia Roja face a must-win game, but les Bleus will doing everything they can to irritate, frustrate and nullify their free-flowing football.
Read on to preview four key battles, both on and off the field.
For the first time in a long time, Spain did not steamroll their weaker opponent in an official match on Friday.
The game against Finland took a David and Goliath billing, yet the match finished 1-1; la Furia Roja are far from invincible, and if they wish to qualify automatically from the group, then this game is considered a must-win scenario.
On the other hand, France have something to hold onto, to fight for, and they've already matched Vicente del Bosque's side once during the qualifying campaign.
This one, on the whole, promises to be positively desperate.
It's interesting to note that a disappointing result for Spain comes off the back of a Xavi absence.
Barcelona struggled with a half-fit version in their loss to AC Milan at San Siro, rested him, and then demolished the Rossoneri in the second leg with his help.
Many don't understand the differences both Xavi and Andres Iniesta bring to the game, but Xavi's importance has been laid bare before us in the last month.
He's expected to be fit for the France clash, so who has the unappealing task of keeping tabs on him? It'll be Blaise Matuidi or Maxime Gonalons, poor souls.
Jordi Alba has been ruled out of Spain's clash with France as he travels back to Barcelona with a hamstring injury.
That leaves the left-back berth wide open for Nacho Monreal—a thoroughly able replacement—to come in and start against top-tier opposition.
Christophe Jallet started against Georgia in the absence of Mathieu Debuchy, and Mathieu Valbuena will likely take up the position on the right wing.
It's a severe test for the more defensively able Monreal, but he's well up to the task.
Didier Deschamps has a tough decision to make up front—Olivier Giroud or Karim Benzema?
Laurent Blanc always brought the former on as a foil, but Deschamps started both in a 4-4-2 against Georgia, and Giroud scored.
There's no way les Bleus will go 4-4-2 against possession-hungry Spain, and Giroud looks like he may well get the nod after Benzema failed to score in his fourth qualifying attempt.
Will he be able to get the better of the in-form Sergio Ramos? It promises to be a tight battle.