Tonight sees Tito Vilanova lead Barca into European action for the first time since taking over from Pep Guardiola at the end of last season. The Catalan giants have started well under their new boss, winning every one of their games in La Liga so far.
Their only defeat has been to Real Madrid in the second leg of the Spanish Super Cup, which cost them the trophy by virtue of the away-goal rule.
Meanwhile, Spartak have endured a patchy start to the Russian Super League, winning four out of their eight games, with one draw.
Please note that kick off is at 7.45pm.
FULL TIMEThe full time whistle blows at the Nou Camp. Unai Emery's wait for a win against Barcelona goes on.
86 minsBarcelona are just keeping the ball now. The seconds are ticking down. Spartak seem to have accepted their fate. They've given it a good go at the Nou Camp. Although it's not over yet...
83 minsAdriano is running at the Spartak defence now and is proving to be a menace. He rolled the ball back for Pedro, but his right-footed effort is off target.
81 minsSanchez clipped a right-footed cross into the box from the left and it was right on Messi's head. A quiet night results in two goals for the Argentinian ace. You can't keep him down.
79 minsGOAL! MESSI SCORES HIS SECOND OF THE NIGHT!
78 minsKim Kallstrom is coming off for Juan Manuel Jurado.
77 minsXavi drives a free kick into the box from the left, but it goes well over.
76 minsDyukin makes a good save from an awkward cross. The ball fell to Villa in the area, but his left-footed shot on goal was blocked.
76 minsXavi taps it to Messi but his arrowed shot cannons off the wall.
75 minsMessi and Xavi stand over a free kick from 20 yards out in the centre of the goal.
74 minsDavid Villa is coming on and Tello is the man making way. Tello has had a good night tonight, it's a slight surprise that he is not being kept on. Still...
73 minsTello showed a touch of class by jinking past McGeady and getting into the box. He pulled it back to Messi, who could not miss an open goal from yards out - despite having a quiet night.
71 minsGOAL! MESSI SCORES FOR BARCELONA!
69 minsthe ballbreaks to Ari on the left, he tries to play a sweeping ball through to McGeady on the right, but Mascherano intercepts it and knocks it out for a corner.
68 minsXavi tries to find Sanchez up top, but his long-range pass is easily cut out by the Spartak defence. It just doesn't seem to be clicking for the hosts tonight.
65 minsSong blazes a header over from a corner. Meanwhile, David Villa is warming up.
64 minsMessi is visibly frustrated tonight. I have never seen him barking at his teammates so much.
63 minsAlexis Sanchez is about to come on. He will replace Dani Alves. The Brazilian will lament the first-half own goal that drew Spartak level. He'll have no chance to redeem himself tonight.
61 minsIt was a fast break, with some tremendous work from Ari down the left. Romulo arrived late into the box and passed the ball beneath Valdes. Shock on the cards at the Nou Camp!
58 minsGOAL! SPARTAK BREAK DOWN THE FIELD AND ROMULO TUCKS PAST VALDES TO PUT THE RUSSIANS IN FRONT!
58 minsCHANCE! It was a hopeful ball swung into the area by Alves. Messi took it down and fired a shot straight at Dyukin.
56 minsEmenike is causing Barca some problems at the back. Busquets has pushed further up the field, leaving Barca a bit thin at the back.
54 minsSpartak have a rare foray forward. However, shots from Carioca and McGeady fails to trouble Valdes.
52 minsBarcelona have picked up from where they left off in the first half and look happy to just retain possession.
47 minsSpartak are making a change. Evgeni Makeev is coming on to replace Kirill Kombarov. His twin brother Dmitry Kombarov is still on the field.
8.46pmThe Barcelona players are back on the field. Short team talk. There's no need for drastic changes, just a bit more urgency.
8.42pmSpartak have defended resolutely. They will need 45 minsutes of the same, as Barca always remain dangerous.
8.41pmMessi and Fabregas have looked a little off the pace so far tonight. Xavi is having a decent game, as is Tello. Pedro has not really been involved.
8.34pmYou can read Sports Mole's Half-Time Report, lovingly prepared by my colleague Mr Callum Mulvihill, by clicking here.
HALF TIMEThere goes the half-time whistle. It's been a subdued performance from Barcelona. They have enjoyed the lion's share of possession, which you would expect, but they have not really created many clear-cut chances. The atmosphere at the Nou Camp just seems a bit flat tonight.
45 minsXavi has a pop from long range but it bobbles past Dyukin's post without troubling him.
44 minsEmenike is booked for not retreating 10 yards for a free kick. Messi tries to whip it in with his left, but once again the execution is way below standard.
42 minsAlves plays a cute reverse pass into Fabregas down the right, and he burts into the area. The defender makes the challenge and it goes out for a corner.
40 minsWe're into the final five minutes of the first half. Barcelona are still chewing the ball. Tello breezes past Kombarov as if he isn't there but his cross poor.
38 minsEmenike is down in the floor clutching his hanstring. Yet more injury woe at the Nou Camp.
36 minsCHANCE! Xavi stabs a ball into the area, Fabregas manages to get free of his marker and get a header in on goal. Dyukin stips over for a corner.
34 minsThere is a bit more vigour in the Spartak ranks since the goal. A bit more belief, maybe. You feel that they need to get to half time on level terms to have any sort of chance of upsetting the odds.
33 minsBusquets flashes a header across the Spartak goal mouth from a corner.
32 minsBarca have a free kick on the left side of the area. Xavi whips it in, but it's a Spartak head that clears the danger.
30 minsEmenike got in behind the Barca defence and tried to square the ball to Ari inside the area. Alex Song tried to clear, but had an air shot. Alves got all he could to prevent Ari from tapping home, but it diverted the ball past Valdes in goal. Unfortunate - and against the run of play - but they all count. 1-1.
28 minsGOAL! AN OWN GOAL BY DANI ALVES DRAWS SPARTAK LEVEL!
27 minsPedro draws a foul from Kombarov just outside the area. Xavi tires to swing one with his right foot but the delivery is poot once again.
26 minsMcGeady gets the chance to break down the right but he is swamped by Barcelona shirts. Mascherano makes the chanllenge and hurts his knee in the process. He's up, but moving gingerly.
24 minsBarcelona have enjoyed 68% possession. Why haven't they had 70%?! Standards are slipping at the Nou Camp...
23 minsIntricate build-up play from BArcelona. Xavi and Messi combine to create an opening but the linesman waes his flag for offside.
20 minsFirst opening of the night for Messi. He gets the ball with his back to goal, turns and shoots. It goes wide of the post. It was a half chance, but not good enough by his own unbelievably high standards.
19 minsOn the bench for Spartak tonight is former Everton wide man Diniyar Bilyaletdinov. his introduction is probably unlikely to change the course of this game, though.
17 minsyou get the feeling that it's already damage limitation for Spartak. Emenike and Ari cut lonely figure in attack for the Russian side.
15 minsTello bent it nicely with his right foot into the bottom left corner. It gets better every time you see it.
14 minsThe Spartak defender committed himself by going to ground too early and Tello stepped inside before shootting past Dykan to notch his first goal of the season. It was a great strike.
13 minsGOAL! TELLO SCORES FOR BARCELONA!
12 minsAlex Song is preparing to come on.
11 minsPique has signalled to the bench that he has to come off. Bad news for the hosts.
10 minsOFFSIDE! Messi plays a glorious ball through to Tello, but he is just offside. Tello missed his chance anyhow.
9 minsMeanwhile, Barca are playing their normal passing game.
8 minsPique is just off the pitch receiving treatment on his ankle. It's in the form of cold spray. No magic sponges here.
6 minsXavi pulled the corner back to the ensuing Pique, but his shot goes well over. He takes a knock on the ankle for his troubles, too.
6 minsBarca have set up camp in Spartak's final third. Some neat interplay ends with Alves slipping Messi through, but Rafael Carioca gets across and concedes a corner.
4 minsSpartak win the first corner of the game. Mascherano denied Emenike in the area with a covering tackle. The corner doesn't beat the first man and is easily cleared by the Barca defence.
3 minsThere's no Puyol or Iniesta tonight. Xavi, Iniesta and Fabregas will no doubt provide the foil for Barcelona. Tello offers some width, as does Pedro, who starts in attack.
2 minsBarcelona have gone for a back three of Pique, Mascherano and Serio Busquets, with Adriano and Dani Alves employed as marauding full-backs.
1 minWe're underway at the Nou Camp.
7.39pmSpartak reached the group stage courtesy of a 3-2 aggregate play-off success over Fenerbahce. A 1-1 draw in Istanbul was enough to seal their progress.
7.35pmBarcelona are unbeaten in 16 European home fixtures since the 2009 defeat to Rubin Kazan.
7.33pmSpartak may have a (not-so)secret weapon tonight. Their coach is well renowned in Spain - former Valencia manager Unai Emery. However, he has never led a team to victory against the Catalan outfit.
7.29pm12 years ago, Geremi - of Middlesbrough, Chelsea and Newcastle fame - scored a 47th-minute own goal in Real Madrid's 1-0 defeat to Spartak Moscow 12 years ago. That was the last time Spartak beat Spanish opposition.
7.23pmThe next two matches resulted in stalemates, but Barca ran out comfortable 2-0 winners in their final contest in December 2010.
7.22pmGoals from Aleksandr Ryazantsev and Gokdeniz Karadeniz helped Rubin to a shock 2-1 win at the Nou Camp in 2009.
7.18pmThe Catalan club have struggled to beat Russian opposition since Frank de Boer scored in a 1-0 triumph over Lokomotiv Moscow in 2002. They have won just one of their last four times in that period; however, they all came against Rubin Kazan in 2009 and 2010.
7.14pmSpartak staged a late comeback to record a 2-2 draw against Barca in the return leg in Moscow.
7.13pmThe two teams were drawn against each other in the group stage of the competition back in 1994. Barcelona trounced Spartak 5-1 at the Nou Camp, thanks to two goals from Ronal Koeman, as well as strikes from Guillermo Amor, Romario and Hristo Stoichkov. Valery Karpin had opened the scoring for the visitors that night.
SPARTAK MOSCOWDykan; Insaurralde, Kombarov, Suchy, Kombarov; Carioca, McGeady, Kallstrom, Romulo; Ari, Emenike
BARCELONAValdes, Alves, Pique, Mascherano, Adriano, Sergio; Fabregas, Xavi, Tello, Messi; Pedro
6.58pmFirstly, some team news...
6.54pmEvening all. Welcome to Sports Mole's live coverage of the UEFA Champions League. Tonight sees Barcelona kick off their campaign at home against Spartak Moscow.