Twelve clubs have already booked their places in the knockout stages of the Champions League going into the final evening of group matches on Wednesday.
Celtic qualified for the knockout stages for the first time under this format of the competition with a home win against Manchester United in November.
Chelsea joined Celtic and Liverpool in the next round, with Arsenal and United needing at least a point in their respective final group games to make it a quintet of British teams in the last 16.
BBC Sport assesses the permutations, with the top two from each group going through and the consolation of a Uefa Cup spot going to the third-placed team.
GROUP E
Dynamo Kiev v Real Madrid
Lyon v Steaua Bucharest
Lyon dropped their first points of the campaign in the penultimate round at Real Madrid but the draw was still enough to secure them top spot.
Real follow them through in second and Steaua picked up a point against Dynamo to ensure they will go into the mix in the Uefa Cup, so this group is done and dusted with a round to go.
GROUP F
FC Copenhagen v Celtic
Manchester United v Benfica
In mid-October Manchester United were cruising into the second round, but two defeats later and they have left themselves needing a draw in the final group match at home to Benfica.
Celtic's victory against Sir Alex Ferguson's side mean they are through and a win will ensure they top the group when they travel to FC Copenhagen, who are sure of finishing with the group's wooden spoon.
GROUP G
Hamburg v CSKA Moscow
Porto v Arsenal
The competition's complicated count-back rules may come into play in this tightest of groups if the top three finish level on points.
CSKA must win in Hamburg but will not go through if the game in Porto ends level. Arsenal and Porto would qualify in the 'mini-table' of results of games involving the trio.
GROUP H
AC Milan v Lille
Anderlecht v AEK Athens
AEK Athens have just won their first two matches ever in the Champions League to get back in the Group H frame and now they need to do something else they have never done to reach the second round - win away.
Lille need to better whatever the Greeks do and they may get a helping hand from AC Milan who are through and may rest some players.