There are two absolutely manic nights of football to come, with every Champions League team playing at the same time on Wednesday before the Europa League sides do the same on Thursday.
Many are looking to seal a top-eight spot that will give them a place in the round of 16, and most of the others are still in with a chance of making the top 24 and thus the knockout playoffs.
Bearing in mind the stakes and permutations, these are the four matches you'll want to keep an especially close eye on.
Wednesday, January 28th
Benfica vs Real Madrid - 21:00 CET
This clash in Lisbon is already tasty given Benfica need a win to stay alive, and Real Madrid could drop out of the top eight if they lose, but it's made particularly enticing by the fact that Los Blancos are reuniting with the 'Special One'.
Not only is Jose Mourinho facing his former club, but he's doing so at a time when there are whispers in the Spanish press that Real Madrid president Florentino Perez wants to bring him back in the summer. If Mourinho can lead Benfica to victory and prove what many doubt, that he's still a world-class coach, those whispers are sure to get louder.
Standing in his way is a former player of his, Alvaro Arbeloa. The two going up against each other is a fascinating subplot given they enjoyed a close player-coach relationship, with the Spaniard dubbing Mourinho an idol and father figure, but there will be no room for sentimentality with Arbeloa knowing a loss would massively hurt his chances of remaining Real Madrid manager beyond the end of the season if it cost them a place in the round of 16.
Benfica sit three points off the playoff places ahead of the match, while Real Madrid are just two above them, so it's all to play for in terms of this season's Champions League, and perhaps even in terms of who will be occupying the Bernabeu dugout next season.
Napoli vs Chelsea - 21:00 CET
Mourinho isn't the only man facing his former employer, with Antonio Conte renewing acquaintances with Chelsea in a clash that both will be desperate to win.
Things aren't going well for Conte right now, with Napoli winning just one of their last six and suffering a 3-0 loss to Juventus at the weekend. As a result of their failure to beat 10-man Copenhagen last week, they're not even making the Champions League playoffs as it stands, and need to beat Chelsea to have any hope of doing so.
Things are going much better for the London side, who have won four of their first five matches under Liam Rosenior and know that another in Naples will most likely see them finish inside the top eight. That would well and truly get the Stamford Bridge faithful, many of whom have been sceptical about his appointment, fully behind their new manager.
For Conte, it's very easy to see another bad defeat and a league-phase exit lead to a complete implosion of his Napoli project, much like the one that ultimately ended his time at Chelsea.
PSG vs Newcastle - 21:00 CET
If you want to focus your attention on just one Champions League match, make it this one.
It's rare that you see a match where both sides genuinely need to win and don't have the backup option of doing so in a penalty shootout, but that's the case here; if neither PSG nor Newcastle are leading this when the full-time whistle blows at the end of 90 minutes, both will almost certainly drop into the playoffs.
They head into it sitting in sixth and seventh, level on points with one another and six clubs below them. As a result, a draw probably wouldn't be good enough for either, meaning they'll both be going for the win.
With more quality and home advantage, the reigning champions are the favourites, but Newcastle smashed them 4-1 before drawing 1-1 in Paris when they met two seasons ago, and have been excellent in Europe this year, conceding the second-fewest goals (6) of any team.
Two top sides that should be closely matched and are in need of a win. This will be fun!
Check out the full Champions League standings here.
Thursday, January 29th
Real Betis vs Feyenoord - 21:00 CET
Over in the Europa League, the standout clash will take place in Sevilla, where two of the competition's biggest clubs will both be desperately seeking three points.
Real Betis looked set to head into the final round of games with a place in the top eight already secured, but a surprise 2-0 loss to PAOK last time out has left Manuel Pellegrini's side just one place and one point above the playoff spots, and as one of the tournament favourites, dropping into them would be a big disappointment.
For Feyenoord, on the flip side, making the playoffs is now the dream scenario after a disastrous run which saw them win just two in 12 in all competitions. An impressive win against Sturm Graz last week at least gave them a slim chance of keeping their European campaign going, and Robin van Persie will need to take it if he wants to alleviate the huge pressure he's now under.
For both the hosts and the Rotterdamers, only a win will be enough for them to achieve their objective, and with the two sides also boasting some thrilling attacking talent between them, this looks set to be a thriller.