Eight of the 32 teams have been eliminated, with the other 24 teams either battling for a place in the knockout stages or to see which team tops each group.
Both sides then went on to win their second games, Portugal against Morocco and Spain against Iran, by a score of one goal to nil, meaning that both their points and goal totals are identical going into their final group games. But while Iran's path to the next round is fairly straightforward, Spain and Portugal are still likely to reach the knockout stage.
Spain and Portugal lead the group with four points apiece, but Iran is just a point behind.
Advances with a win over Portugal. Can advance with a loss if Spain loses to Morocco and it beats Spain on goal differential. Even if Iran contains Ronaldo, Portugal has enough weapons to get a goal - and that could be enough.
Iran: Will qualify only if they beat Portugal.
Switzerland will qualify with a win against Costa Rica, with a draw also good enough as long as Serbia don't beat Brazil.
Advances with a win over Croatia and a better goal differential than Nigeria. A point against Iceland will see them in as winners, but their strong goal difference has practically secured that anyway.
Advances with a win over Argentina. A draw would also send them through, though winning the group would depend on Switzerland's result against Costa Rica. If they both win then the team with the biggest win will finish top of Group B.
Similar to Group B insofar as wins or draws for the top two will see both through.
Switzerland and Brazil only need a draw draws to go through, while it's a must-win for Serbia against Brazil on Thursday at 6am.
Mexico need only a point against Sweden to qualify and finish top.
Sweden can qualify with a win over Mexico and a Germany loss to South Korea.
Germany, who face bottom side South Korea, need to at least match Sweden's result. The victor takes it. England are ahead on the disciplinary front with one fewer yellow card than Belgium.
Japan sit in the box seat here, as they meet winless, hapless and eliminated Poland on Friday at 2am.
A draw would do it for Japan, same for Senegal, but Colombia hit form against Poland on Monday and could be too strong for their African opposition.