Yesterday evening the outcome of three Champions League groups was decided, with the snow and hail in Istanbul meaning that Galatasaray and Juventus will have to wait until this afternoon to play for the right to join Group B winners Real Madrid in the last 16 of the competition.
The teams in the final four groups will seal their respective fates tonight, with something to play for in each of them.
Here, Sports Mole has analysed the permutations for all of the 16 clubs involved.
GROUP E
It has been by no means emphatically done, but Chelsea have qualified for the knockout stages with a game to spare. If the West Londoners can dispose of Steaua Bucuresti at Stamford Bridge, they will advance as group winners.
Anything less will open up the door for Schalke 04 and Basel, who meet in Germany. The away side currently hold the advantage in the second spot, but a win for Schalke will see them progress at the Swiss side's expense. If Chelsea were to lose, a win for either would see them top the standings.
Meanwhile, there is little more than pride to play for as far as bottom team Steaua are concerned.
FIXTURES: Chelsea vs. Bucuresti, Schalke vs. Basel
GROUP F
Premier League leaders Arsenal have 12 points to their name, and yet they still have not qualified. A win or a draw in Naples will seal their passage through as group winners, but a defeat throws their progress into the realms of uncertainty.
Borussia Dortmund, who take on Marseille in France, will go through if they win or match what Napoli do against the Gunners. They can also top the table, but only if they win and Arsenal lose, providing that it isn't by a one-goal margin of 4-3 or higher.
As for Napoli, they can go through by either bettering Dortmund's result against Marseille, or by defeating Arsenal by a three-goal margin or more.
There are no such problems for Marseille, who are out of Europe regardless of what they do against Jurgen Klopp's charges.
FIXTURES: Marseille vs. Dortmund, Napoli vs. Arsenal
GROUP G
Thirteen points from a possible 15 have seen Diego Simeone's Atletico Madrid cruise through as group victors.
However, while they have little to play for, the same cannot be said for their visitors Porto. The Portuguese side must win in the Vicente Calderon and hope that Zenit St Petersburg fail in their pursuit of the three points against Austria Vienna.
The head to head record stands in Zenit's favour, while the other team in the group, Vienna, have already been eliminated.
FIXTURES: Atletico Madrid vs. Porto, Vienna vs. Zenit
GROUP H
Believe it or not, Barcelona have not won their group just yet. They have already qualified and will confirm themselves as leaders courtesy of a victory over Celtic in the Camp Nou.
The other match, which will see AC Milan play host to Ajax, is a straight shootout. The winner will go through, with the draw in Milan's favour as they currently hold a one-point advantage over their Dutch visitors. Milan can still top the group as well, but only if they win and Celtic defeat Barca.
Staying with Neil Lennon's Celtic, they will finish bottom regardless of this evening's results.
FIXTURES: Barcelona vs. Celtic, AC Milan vs. Ajax