The Champions League group stage has reached its business end seemingly in the blink of an eye, with Liverpool becoming the first English representative to book their spot in the last-16 on Wednesday night.
They did so with another dazzling display against Diego Simeone's Atletico Madrid, strolling past the Spaniards 2-0 at Anfield to claim their fourth win in as many outings and secure their spot as Group B winners.
Fellow European giants Ajax also needed just four games to confirm their progression out of the group with a highly impressive 3-1 win away at German outfit Borussia Dortmund, who are now in a battle to qualify for the knockout stages.
Previously, on Tuesday night, powerhouses Bayern Munich and Juventus booked their spots in the draw for the last-16, which will take place in mid-December.
There is still plenty to play for with two sets of fixtures remaining, with plenty of work to do yet for the likes of Manchester United, Atletico Madrid and Barcelona, while Manchester City and Chelsea are in a strong position.
Sportsmail takes you through the state of play as the Champions League group stage approaches its close below.
Who has qualified for the Champions League last-16?
As stated, four teams have now qualified for the Champions League knockout stages, though only one has guaranteed a place as group winner.
That was Liverpool, whose fine victory over Atletico Madrid capped what has been a scintillating group stage thus far.
They previously battled past Italian giants AC Milan in a 3-2 thriller at Anfield, before handing Porto - who they just love to play - a 5-1 hiding on Portuguese soil. They also beat Atletico 3-2 in the reverse fixture at the Wanda Metropolitano Stadium.
Ajax have also enjoyed a perfect start to their Champions League campaign, with their 3-1 victory over Dortmund adding to a 4-0 win over the German giants on home turf, alongside a 2-0 win over Beskitas and a 5-1 romp against Portuguese outfit Sporting Lisbon.
Two elites of the game Bayern and Juventus sealed their progression to the last-16 on Tuesday, both maintaining perfect records with respective wins over Benfica and Zenit St. Petersburg.
Bayern had previously emphatically beaten Barcelona at the Nou Camp, before claiming further victories - and clean sheets - over Dynamo Kiev and Benfica.
Juventus, meanwhile, previously earned wins over Malmo, Chelsea and Zenit.
Who is still fighting to qualify?
Group A: Manchester City, Paris Saint-Germain and Club Brugge
Manchester City all-but confirmed their progress to the Champions League knockout stages with a convincing 4-1 win at home to Club Brugge on Wednesday night.
Last year's finalists, who fell short once more as Thomas Tuchel guided Chelsea to an historic triumph, can seal their spot in the last-16 with a game to play should they beat Paris Saint-Germain on November 24.
A draw would also be sufficient for both sides, so long as Club Brugge don't win at home to RB Leipzig.
And while that once was a perhaps likely predicament, Leipzig are enduring a woeful season following Julian Nagelsmann's departure to Bayern, sat ninth in the Bundesliga table and already crashing out of the Champions League.
They can still battle it out for a Europa League spot, with the team finishing in third dropping into the competition, with their clash against Club Brugge next up set to be a fascinating watch.
PSG, who are yet to gel fully under Mauricio Pochettino and with Lionel Messi in the team, still have work to do. A loss against City next up could set up a mouthwatering final-day tie against Club Brugge in early December.
Remaining Group A fixtures
Group B: Porto, Atletico Madrid and AC Milan
Liverpool, as stated, have already claimed top-spot in Group B, but the runner-up spot place remains open to the other three participants.
The punters out there would have counted on Atletico Madrid to join Liverpool in the last-16, but after falling to back-to-back defeats to the in-form side, they now face a real battle for a place.
It's Porto who have the advantage after four fixtures, and wins over Liverpool and Atletico Madrid would see them progress to the knockout stage.
Beating Liverpool in the form they're in is a tough ask, however, and with Atletico coming up against struggling AC Milan next, it's the Spaniards who could have the advantage going into matchday six.
There, a fascinating final-day clash between Porto and Atletico will take place, while AC Milan face a tricky home tie against Liverpool as they look to salvage a place in the top three.
Remaining Group B fixtures
Group C: Borussia Dortmund and Sporting Lisbon
Ajax have already topped Group C, while Besiktas relinquished their spot in European competition this season with a 4-0 drubbing at Sporting Lisbon on Wednesday.
It's up to Sporting and Dortmund to determine who progresses into the last-16 and who drops into the Europa League, with an all-important clash between the pair next up on November 24 in Portugal.
Dortmund, who won the reverse fixture 1-0, would qualify for the knockouts with another win over Sporting, regardless of what happens on matchday six, by virtue of a better head-to-head record.
As for Sporting, a win by more than one goal would see them finish in second place for the same reason. A draw, however, would leave the group open once more, with Dortmund at home to Besiktas on the final day, while Sporting travel to Ajax.
Remaining Group C fixtures
Group D: Real Madrid, Inter Milan, Sheriff Tiraspol and Shakhtar Donetsk
Following the draw for the Champions League group stage, Group D is one that was perhaps deemed a write off, with Real Madrid and Inter Milan expected to qualify with ease.
They are indeed the top-two, but Moldovan outfit Sheriff have proven to be one of the surprise packages of the tournament, already securing a shock win over Los Blancos and looking almost certain to gain a Europa League spot at the very least.
Madrid and Inter are set to meet on matchday six, but they both could have secured spots in the knockouts beforehand should they win their respective games against Shakhtar Donetsk and Sheriff. The match-up would then decide who would progress as group leaders.
Should the unthinkable happen and Sheriff topple Madrid once more, this time on home soil, they would go above the European giants heading into the final clash.
Shakhtar can still technically make the runner-up spot their own should they beat both Inter and Sheriff - who would have to lose against Madrid - having drawn with the the Italians to gain their one and only point thus far. That seems unlikely, however.
Remaining Group D fixtures
Group E: Barcelona, Benfica and Dynamo Kiev
Barcelona endured a woeful start to their Group E campaign, falling to back-to-back 3-0 defeats to Bayern and Benfica.
The Catalan club have fought back into second place, however, with a pair of 1-0 wins over Dynamo Kyiv, the latter of which being the club's first Champions League outing since the dismissal of Ronald Koeman, with interim boss Sergi Barjuan taking charge.
Up next for Barcelona is a home tie against Benfica, whereby a win would be enough to see them progress to the knockout stage as group runners-up.
A win for Benfica, who were thumped twice by Bayern, would see them in the ascendancy with a game against bottom side Dynamo Kyiv to finish the group.
Remaining Group E fixtures
Group F: Manchester United, Villarreal, Atalanta and Young Boys
Group F is still wide open with two games to play, though Manchester United are in pole position after a crucial last-gasp Cristiano Ronaldo equaliser in a 2-2 draw away at Atalanta on Tuesday.
Ronaldo has been a pivotal figure for United throughout their Champions League campaign, which started with a highly disappointing 2-1 defeat away at Young Boys.
United won consecutive games against Villarreal and Atalanta, with Ronaldo snatching late winners in both, before the Portuguese superstar bailed them out once more in a draw against the Italians.
Having beaten Villarreal in the reverse fixture at Old Trafford, United can now secure their progression to the last-16 with a win over the Spaniards on November 23.
A loss would put them in a difficult scenario, however, likely in third place going into matchday six with Atalanta taking on Young Boys next up.
The battle for second, at the very least, will certainly go down to the final day.
Remaining Group F fixtures
Group G: RB Salzburg, Lille, Wolfsburg and Sevilla
All four teams are still able to qualify for the knockouts in a highly competitive Group G, though it's RB Salzburg who lead the way after four games.
The group was blown wide open as Salzburg fell to a 2-1 defeat to Wolfsburg on Tuesday, however, while Lille more than kept their chances alive with an impressive 2-1 win away at Sevilla.
Salzburg will progress to the knockout stages should they beat Lille in their next fixture on November 23, having claimed victory over the French side in the reverse fixture.
Meanwhile, Sevilla, who may not even get into the Europa League at this stage, will square off against Wolfsburg in another intriguing encounter.
There are set to be plenty of twists and turns yet in this group, which will run down to the final day.
Remaining Group G fixtures
Group H: Chelsea and Zenit St Petersburg
Lastly, we have Group H, which is pretty much already decided. Juventus sealed their spot in the last-16 on Tuesday, with their fourth win in as many matches.
Meanwhile, Chelsea moved to nine points with a 1-0 away win over Malmo, and just a draw in their following encounter against Juventus would be enough to secure their progression to the knockout stage.
If Chelsea are to lose, however, then Zenit still have a chance - providing they beat Malmo in their respective clash.
Chelsea beat Zenit 1-0 in the clash at Stamford Bridge back in September but if it comes down to the final day, the Russian's would pinch a place if they can win by more than one goal.
Malmo, who have lost all four of their matches, are out.
Remaining Group H fixtures