[CHAMPIONS LEAGUE] Six teams are vying for the final three places in the round of 16, half the groups have yet to decide a winner and the tournament's defending champion is on the brink of unprecedented elimination.

Entering the final week of group play, 13 knockout round tickets have been punched. One team from each of these three pairs will join them, after all six play other clubs Wednesday: Juventus or Chelsea; Benfica or Celtic; Galatasaray or CFR Cluj.

Four prized top seeds are still up for grabs, as group winners face runners-up from other groups, starting in February. Head-to-head tiebreaking, favored by UEFA, played a big role in seeding and qualifying.

We streamlined the standings, ignoring the Europa League ramifications, leaving remaining clubs, relevant games, and what’s at stake. Teams in bold have advanced …

Tuesday
Group A: Paris Saint-Germain-FC Porto

Both teams are through. Porto wins the group with a tie or better in Paris, while a win by PSG sees it top the group. This is one of two games in round six where the only possible winners settle it on the field, the other in Group E.

Group B: Olympiakos-Arsenal, Montpellier-Schalke 04.

Schalke and Arsenal are through, the Gunners for a 13th year in a row. Arsenal will finish second unless it wins in Greece and Schalke fails to win in France.

Group C: Malaga is the winner, AC Milan finished second.

Group D: Borussia Dortmund takes first after besting Madrid over two legs. Real Madrid is through for the 16th year in a row, and a nightmare No. 2 seed for some unlucky group winner.

Wednesday
Group E: Shakhtar Donetsk-Juventus, Chelsea-FC Nordsjaelland

Shakhtar has advanced, taking first with a tie or better. Juve is second with a tie, and wins the group by beating Shakhtar. The only way Chelsea advances is by beating FCN while Juve loses, also the only way Juve is eliminated.

The Italian champion is the only team that can still finish first, second or be knocked out, while Chelsea is on the brink of becoming the first defending champion ever eliminated before the knockout phase.

Group F: Bayern Munich-BATE Borisov, Lille-Valencia

Bayern and Valencia are through. Bayern owns the tiebreaker, and wins the group with an equal or better result than Valencia.

Group G: Barcelona-Benfica, Celtic-Spartak Moscow

Barcelona won this group. Benfica and Celtic have 7 points. Benfica owns the tiebreaker, and goes through with an equal or better result, however, the Scottish champion is hosting Spartak, whereas Benfica visits Barcelona.

Group H: Manchester United-CFR Cluj, Braga-Galatasaray

Manchester United won what may be the weakest group. Galatasaray and Cluj both have 7 points Galatasaray owns the tiebreaker and qualifies with an equal or better result. Cluj will hope for a motivated Braga, and the second string at Old Trafford.