Over the next two matchdays, 32 teams will become 16, as clubs vie for limited berths in the continent’s premier cup competition.
snl24.com/kickoff takes a look at the eight matches taking place tonight, and all the possible permutations of the 16 clubs in action.
GROUP E
Bundesliga champions Bayern Munich have comfortably qualified as group winners with four wins from four, yet face reigning Premier League champions Manchester City tonight in what is a must-win encounter for the English club, who are two points adrift of joint second-placed Roma and CSKA Moscow.
A win for either the Italians or Russians, combined with a draw or loss against Bayern, will spell the end for City - and their third group stage exit from the competition in the last four years.
A draw in both of tonight’s fixtures means City are still in with a chance, but will have it all to do in Rome in the last round of group fixtures in two weeks’ time.
GROUP F
Paris Saint-Germain and Barcelona have both already reserved their spots in the Last 16 of the tournament, as Ajax and APOEL fight it out for the remaining Europa League spot.
Yet both the French and Spanish giants will be looking to finish top of the group, with PSG currently leading the Catalans by one point.
They will however face-off at the Camp Nou in Matchday 6 which could be the decider, should both PSG and Barca emerge victorious tonight against Ajax and APOEL respectively.
GROUP G
Group G hangs very much in the balance, with one slip up for second-placed Schalke 04 allowing either Sporting or Maribor to have a sniff at qualification.
Group leaders Chelsea will be through as winners with a win in Germany tonight, while bottom-placed Maribor will be out if they lose against Sporting. A win for the Portuguese, combined with a Schalke loss, will see Sporting over-take the Germans into second place, yet they still have a tough fixture against Chelsea in two weeks’ time.
GROUP H
In Group H, Porto have already qualified and could win the group with victory tonight if Shakhtar Donetsk fail to record all three points against Athletic Bilbao.
Bilbao are already out of the running with just one point from their four games, but are still aiming for a Europa League berth as they hope BATE fail to win against the Portuguese tonight.
All Tuesday night Champions League fixtures:
Manchester City vs Bayern Munich
CSKA Moskva vs Roma
APOEL vs Barcelona
PSG vs Ajax
Schalke 04 vs Chelsea
Sporting CP vs Maribor
BATE vs Porto
Shakhtar Donetsk vs Athletic Club