Celtic hosted Spartak Moscow tonight knowing that if they bettered Benfica's result in Barcelona they would qualify for the Champions League last 16.
Kris Commons netted a match-winning penalty late in the second period to earn the Hoops victory, while Barca held their Portuguese opponents at the Nou Camp.
That combination of results means that Celtic have progressed as Group G runners-up, with the Spanish giants topping the pool.
Below, you can read how Neil Lennon's side elongated their fantastic European campaign with a brave victory.
Good evening! Let's get down to business straight away and discuss tonight's starting lineups...
The big news comes from the Celtic camp, with captain Scott Brown passed fit to feature from the off. The Scotland international has delayed hip surgery to play in tonight's crucial clash.
He will replace the influential Victor Wanyama in midfield, whose performances in Celtic's 2012 Champions League campaign have attracted interest from some of Europe's top clubs.
However, the 21-year-old misses out tonight due to suspension after a booking in Benfica took him over the disciplinary points limit.
The versatile Charlie Mulgrew will start on the left wing, with Spaniard Emilio Izaguirre, who has recently recovered from injury, behind him in defence.
Here is the Celtic XI in full...
CELTIC: Forster; Lustig, Ambrose, Wilson, Izaguirre; Commons, Brown, Kayal, Mulgrew; Samaras, Hooper
SUBS: Aluska, Matthews, Ledley, Rogne, Miku, Lassad, Watt
And now onto the visitors, who are bottom of Group G with three points from five games and out of the qualification picture altogether.
SPARTAK: Pesiakov, Kirill Kombarov, Insaurralde, Suchy, Dmitri Kombarov, Rafael Carioca, Kallstrom, Jurado, Dzjuba, Ari, Emenike
SUBS: Dykan, Bryzgalov, Pareja, McGeady, Yakovlev, De Zeeuw, Kozlov
As you can see, Aiden McGeady is, at least initially, being denied an emotional return to Celtic Park after being left on the Spartak bench this evening.
There are, however, a few familiar names in the Moscow XI...
Swedish midfielder Kim Kallstrom has plenty of experience at this level having featured in the Champions League with Lyon prior to his move to Russia.
He will attempt to pull the strings from a Spartak midfield that also includes on-loan Schalke star Jose Manuel Jurado.
The players emerge from the Parkhead tunnel to a raucous ovation from the expectant home fans, who raise the volume even further when that famous Champions League music comes on...
There are around 60,000 people crammed into Celtic Park tonight on a frosty Glasgow night, but those cold conditions will not deter the visitors.
And the action is underway, very promptly, at Celtic Park...
Remember, the Hoops need to better Benfica's result in Barcelona to secure qualification. I'll also be keeping you up to date with the latest score from Spain...
Commons goes in late on Jurado but the referee is reluctant to issue an early yellow card in this match that means so much to the hosts.
Celtic would surely feel a sense of injustice if they do not progress to the knockout stages after their heroics against Barca, who they famously beat in Glasgow last month.
A poor defensive header from Beram Kayal gives Spartak the chance to counter, but Kelvin Wilson does excellently to get across and foil the charging Emmanuel Emenike.
Celtic will be anxious to get on the ball to calm any nerves, as it has mostly been the Russians in possession during the opening stages.
Lustig lumps a long ball forward and Georgios Samaras climbs well, but his knockdown is just ahead of Gary Hooper and Moscow keeper Sergei Pesyakov can claim.
Dmitri Kombarov shows a great change of pace to surge past the defensively-reluctant Commons and fizz in an inviting low cross, which is eventually cleared by Efe Ambrose.
Good interplay between Brown and Commons, who shows lightning-quick feet to evade two Spartak challenges and feed Mulgrew out on the left. He whips a dangerous cross in but Pesyakov comes off his line well to intercept.
SHOT! We have our first effort on goal of the evening as Kallstrom plays a one-two with Artem Dzyuba before bending a shot a few yards wide of Fraser Forster's post.
SHOT! Another halfchance for the visitors as Emenike gets in down the right channel but blazes a shot over the crossbar from a tight angle.
GOAL! Celtic 1-0 Spartak Moscow (Gary Hooper)
Out of nowhere Celtic lead and the home crowd go bananas! Samaras's hopeful through ball is aimed straight at Juan Insaurralde, but the Argentine defender lets the ball straight through him and Hooper is in on goal. The England hopeful strikes it first time from the edge of the area and his effort squeezes under the keeper!
SHOT! The visitors come close to an immediate equaliser as Emenike wrong-foots Ambrose before firing a powerful shot narrowly wide.
Despite the goal, Spartak are continuing to enjoy the majority of the play. They have dominated possession with 65%.
More excellent work from Emenike, who is definitely Spartak's main attacking threat. He skips past Wilson before holding off the former Nottingham Forest man and forcing a corner.
A bustling run from Izaguirre wins Celtic a corner at the other end.
SHOT! The corner is partially cleared to Commons on the edge of the box and he strikes a superb half-volley which finishes just a few feet wide.
SHOT! A clever reverse pass from Commons finds the overlapping Lustig, whose cutback is curled tamely goalwards by Brown. Spartak keeper Pesyakov doesn't need to move to catch that one.
GOAL! Celtic 1-1 Spartak Moscow (Ari)
What a goal this is. Emenike shows great strength and skill to avoid three Celtic challenges on his surge to the edge of the area. Izaguirre has not tracked his runner, Ari, who collects a pass from Emenikie before his delightful chip sneaks under the crossbar despite the best efforts of both Forster and Wilson.
Yellow card! Beram Kayal picks up the first caution of the night for a late tackle on the fleet-footed Jurado.
With Benfica still holding Barca at the Nou Camp, this result would now not be enough for the Hoops to qualify for the last 16.
Mulgrew delivers a cross from deep on the left but Insaurralde rises to head it clear.
HALF-TIME: Celtic 1-1 Spartak Moscow
Want a reflection of the opening 45 minutes? Read Sports Mole's half-time report.
HALF-TIME: This night is supposed to be all about Celtic, but Spartak have been much the better side and fully deserve their half-time parity. The pacey and strong Emenike is proving a constant danger and had a large hand in the Moscow goal, which was subtly finished by Brazilian striker Ari. Gary Hooper had earlier capitalised on a defensive clangor to put the Hoops ahead, but unless Barca can score against Benfica, Celtic will need Hooper and company to find the net again in this second period to keep their qualification hopes alive.
The play has resumed at Parkhead, and in Catalonia, from where you can follow the action here.
SHOT! Patient passing from Celtic eventually leads to Brown being found unmarked, but the skipper's soft effort is blocked by Marek Suchy.
OFF THE POST! Samaras has the keeper beaten, but strikes the woodwork with a sweeping first-time volley from Lustig's low cross. Celtic have started the second half very brightly!
Yellow card! Lustig follows teammate Kayal into the book for a lunging challenge on Kallstrom. The full-back gets a large chunk of the ball, but he slid in with some force and is cautioned for his enthusiasm, such is football nowadays.
Yellow card! Kallstrom now enters the book himself for a similar challenge on Commons.
CHANCE! Samaras is looking particularly lively and he makes up good ground to retrieve the ball and lay it back for Izaguirre to cross for Hooper, whose back-post header is saved easily by Pesyakov.
SUBSTITUTION: Former Celtic man Aiden Mcgeady enters the action to a warm reception, replacing goalscorer Ari. Surely he would not be the man to deny those supporters who once loved him their European dreams?
McGeady’s introduction is simultaneous with another important substitution. The rested Lionel Messi has been brought on for Barcelona, which gives Celtic greater hope of Benfica being denied a crucial point in Spain.
SHOT! Dzyuba is given space to run into and takes on the invitation to strike at goal, but Forster comfortably gathers his low effort.
SUBSTITUTION: While making a charging run forward, Lustig seems to have pulled his groin and is forced off. Adam Matthews is on in his place.
SHOT! Commons jinks in between two Moscow challenges before a shot on his weaker right foot is diverted behind for a corner.
CHANCE! Ambrose meets a Commons corner well at the near post but his header goes into the side netting.
SUBSTITUTION: Lennon makes a positive change and he needs to at this stage. Tunisian striker Lassad Nouioui comes on for his Champions League debut to replace the booked Beram Kayal.
Yellow card! The card count is now even at two apiece as Dmitri Kombarov is shown a yellow for a lunge on Mulgrew.
SAVE! Celtic have some joy from set pieces again as Mulgrew heads a Commons corner into the ground and forces Pesyakov into an acrobatic tip over the bar.
PENALTY! Samaras controls it on his chest and spins away from Suchy, drawing the slightest bit of contact from the Czech on his way to the floor. The referee points to the spot and Samaras punches the air with delight!
GOAL! Celtic 2-1 Spartak Moscow (Kris Commons)
GOAL! Commons smashes it powerfully and the ball rattles the crossbar on its way over the line. Neil Lennon could not watch the spot kick but turns around just in time to join in the celebrations!
Yellow card! McGeady is cautioned for a petulant slide on Samaras which angers the home crowd.
RED CARD! Kallstrom is given his marching orders on his 50th Champions League appearance. He is issued a second yellow and a subsequent red for a horrible tackle on Commons.
Unfortunately for the hosts, Commons has suffered some damage in the same incident and follows Kallstrom down the tunnel on a stretcher. With Lennon having made three changes already, Celtic will also play the remaining minutes with 10 men.
We are now entering stoppage time, of which there will be FIVE minutes!
Excellent ball retention from Samaras buys his side a free kick and a few more precious seconds...
It has ended 0-0 between Benfica and Barcelona in Catalonia, meaning Celtic will qualify if they can hang on in these latter stages!
FULL-TIME: Celtic 2-1 Spartak Moscow - Celtic are through to the Champions League last 16!
The Parkhead faithful are louder than I have ever heard them as Lennon and his players take a lap of honour. This result means there will be more European nights like this in Glasgow later on in the season!
You can read Sports Mole's full-time report on the contest here.
Deep breath! That is it from me for this evening. Thanks for joining Sports Mole for this historic Celtic victory tonight. And the Hoops go marching on...
