Kick off is at 7.45pm (BST). Sean will be here with the pre-match build-up and all the team news from 7.00pm.

Preamble: So where shall we start the bidding? Three goals? Four? Five? At first glance this should be a canter: Barcelona are, well, Barcelona. They've lifted the Champions League trophy three times since 2006, are unbeaten at home in Europe for three years, and have the best player and playmaker in the world. Yet, for now at least, the 4,730 Celtic supporters at the Camp Nou are gazing back, misty-eyed, to 2004, when the Hoops drew twice at Barcelona and clinging to an unlikely repeat. They couldn't do it again, could they?

Well, no ... ... Most of the starting XI that faced Barcelona in 2004 were veterans of the 2003 Uefa Cup campaign, which saw the Hoops reach the final before losing to Jose Mourinho's spoiling, diving, super-cynical Porto side in a minor classic. On their day Martin O'Neill's side could beat anyone. But this 2012 Celtic vintage, while admirable in many ways, isn't in that class. Drop them into the Premier League and they'd surely be fighting to stay up [mbm reporter ducks for cover].

Team news:

Barcelona (4-1-2-3): Valdés, Adriano, Mascherano, Bartra, Song, Jordi, Alba, Xavi, Iniesta, Pedro, Messi, Alexis. Subs: Pinto, Montoya, Cesc, Dos Santos, Sergi Roberto, Villa, Tello.

Celtic (9-0-1): Forster, Lustig, Wilson, Ambrose, Izaguirre, Mulgrew, Brown, Ledley, Wanyama, Samaras, Hooper.

Reasons to be cheerful for Celtic fans: Sergio Busquets, who is suspended, plus Alves, Piqué, Puyol, Thiago, Cuenca and Muniesa will also miss tonight's match. Their defence conceded four at the weekend. Any others?

1 min We're off! Celtic, kicking from right-to-left on my TV
screen, gets things underway. I'm having the odd technical gremlin so
forgive me if the updates are patchier than a band of particularly
unruly pirates for a bit.

3 min Barcelona immediately gain possession and are already
probing for weaknesses. Messi finds Alexis ... who puts it wide. What
a chance! Meanwhile Colin Wan writes: "Fabregas has got to be
absolutely gutted not to be in the team today. He was brilliant
against Deportivo. And I think Messi likes playing with him. Though I
bet Messi could probably score if they blindfolded him, forced him
into and England shirt and made him take a penalty in a game against
Germany."

5 min And so it continues, left to right and back end, with
Xavi conducting the orchestra. An early goal here and this could be a
hiding ...

7 min A long ball is pumped forward by Forster, flicked on by
Samaras and then Brown fouls. You suspect it will be the first of many
tonight.

10 min Alba's cross scoots along the six yard box but Celtic
are able to clear. They're conceding a lot of possession, but that was
always going to be the case. "Well, so far Celtic are categorically
the best British team in Europe. Well done, them," says Matt Dony, not
unreasonably.

14 min Decent stuff from Celtic, particularly down the left
with Samaras and Izaguirre linking nicely. Meanwhile Scott Brown makes
his presence felt, and concedes a foul.

16 min Pass. Pass. Pass. Pass. Pass. Pass. Pass. Pass. Tackle.
Celtic are defending so deep here ...

17 min Drama! First Forster saves and then almost immediately
Celtic, who have been inviting all sorts of pressure, nearly
rope-a-dope Barcelona. The Hoops have a three-on-three for a second,
but it's cleared.

18 min GOAL! CELTIC ARE AHEAD! Barcelona 0-1 Celtic (Mascherano OG
18)
Charlie Mulgrew skizzles one in, it hits Samaras's shoulder
pinballs on to Mascherano and into the net. Incredible scenes at the
Camp Nou!

21 min Barcelona continue to patiently probe. They could be 1-0
up or 0-1 down here; you wouldn't know the difference in the style of
their play.

22 min Meanwhile Ryan Dunne emails in: "I'm personally a
Glorious Glasgow Rangers fan myself, but dare I say that many a Celtic
fan would regard their team as Scottish/Irish (not necessarily a
criticism; afterall, Barca are Catalan) rather than being the British
anything. Fair play though, the O'Neil Celtic were powerful and
exciting. I'm no Jonathan Wilson, but is the O'Neil favourite 3-5-2
really as dour as people allege? Galloping wingers! Two up Front! At
least one creative central midfielder! What's not to love?"
Please consider the environment before printing this email.

24 min Messi powers a free-kick this close over the bar.
It had fizz, dip and Boltesque pace ... it was just an inch or so too
high.

26 min There was a moment there when Barcelona were
tiki-taki-ing the ball about when Celtic had eight defenders and their
keeper in the penalty box. And still Alba, trying to run onto a
throughball, is given offside.

28 min Meanwhile spare a thought for David Goldstone: "Many
months ago I booked a romantic two night break to Barcelona, staying
at an indescribably chic and expensive hotel in a peaceful square just
off La Ramblas. Brilliantly I managed to choose the two nights when
Celtic were in town. No sleep last night. If they win and we have
another sleepless night being serenaded by the green and whites then
my marriage is seriously over. Come on Messi. Do it for me." Win or
lose tonight David, I suspect you're going to be "serenaded" again.

29 min Big miss from Marc Bartra! From a corner, Iniesta, who
has perhaps been an octave or two below his searing best so far, sends
a swirling cross that Bartra meets six yards out ... and glances wide.
He should have scored there.

31 min Meanwhile Ryan Dunne is back. "Yikes, some crazy
scorelines tonight! I'm sure I cant' be the only, Sean, wondering if
yourself or Barry G have a bet on Man U, Barca and Chelsea all losing
tonight, and if so, what sort of odds you got ( a bajillion to one?)"
This will sound like aftertiming but my only bet tonight is both teams
to score in this game at 6-4. Fingers crossed ...

33 min Still Barcelona stick resolutely to plan A, but the
speed of their passing has increased. Celtic's formation is now very
much 5-4-1. Barcelona win another corner but Adriano's skidding shot
from 24 yards is saved at his near post by Forster.

35 min Scott Brown pushes, barges, harries and annoys Messi -
all in the space of a few seconds - before conceding a foul. For all
their possession, Barcelona have created - what - three decent chances
so far?

37 min Again come the slow handclaps ... clap ... clap ...
clap ... as Messi lines up a free-kick, 25 yards out, central. Then -
for a millisecond - silence before a huge 'Oooooooooooooh' of
exhalation as Messi's free-kick hits the netting over the bar.

38 min Samaras is hobbling here after rolling over his ankle.
Surely he can't continue here? Meanwhile this from Gordon Pittendrigh:
"I'm a Celtic fan trying to remember to breathe here. Not sure whether
to watch rest of game or DVD of The Alamo."

42 min With Samaras off, and James Forrest waiting to come on,
Barcelona keep the torture going against the 10-men but again it comes
to nothing.

44 min Celtic sub: Forrest on, Samaras off. Celtic are
desperately hanging on for half-time here.

GOAL! Barcelona 1-1 Celtic (Iniesta 45m) A wonderful, wonderful goal for Barcelona - five, six passes in a blink of an eye, with Xavi
and Iniesta key, before the later takes a throughball on the half-turn and slots it into the corner. That was everything Barcelona stand for, right there.

Half-time Just before the referee's whistle, Messi dragged a half-chance wide. So it's 1-1 at half-time after a riveting first half. Meanwhile Colin Owens wrote this a few minutes ago: "With Braga 2-0 ahead and Celtic 1-0 up I hastily deposited €10 into my Paddy Power account for a Barca/Utd double as I know too well that good things don't last!" Looks like you might have a shot there, Colin ...

46 min Barcelona get the second half underway. "I'm not sure if its the same for everyone, but this MBM is appearing on my phone with lots of line breaks, giving it the appearance of blank verse," says Matt Dony. It lends a Shakespearean dignity and gravitas to Barca's dinky little sideways passes."

48 min It's as you were: Barcelona continue to probe, particularly with the Alba-Alexis-Iniesta triangle down the left, while Celtic remain steadfast for now. The vistor's aim is to play the ball into Hooper and try to get runners off him. And it works there, as after five or six passes they win a free-kick in a dangerous. Mulgrew steps up ...

49 min ... and crashes it against the wall, which was about five yards back. The follow up shot from Izaguirre balloons into the crowd.

51 min Lovely twist-and-pass from Iniesta to Messi, who immediately brings the ball to heel before attempting a 9-iron over the 6ft 7in Forster. It doesn't miss by very much...

53 min So close for Celtic! Barcelona can't defend set-pieces at all. Another flighty corner from Mulgrew spins violently across the six-yard box, flicking the head of two Celtic players before going wide. Neil Lennon, watching on the sidelines, has his head in his hands.

56 min It's almost all Barcelona here. Forster has just saved a straightforward shot from Adriano. "I can confirm that I'm not seeing any unusual formatting," says, er, Mister Justi. "I'm currently on a Windows XP SP3 machine with Google Chrome version 22.0.1229.4m which is "up to date". Also I'm regionalized to Canada. I'll get my video driver details if you should like too." Hands up who fancies going to a party at Justi's house afterwards?

59 min For a second there Celtic had a two-on-two but Victor Wanyama dallies and dillies and is tackled. Meanwhile Martin Mckeefry has some relationship advice for David Goldstone (28 min), who emailed in from his posh hotel near Las Ramblas.: "If his idea of a romantic break even involves logging on to a computer, let alone a min-by-min report, then his marrage etc etc."

60 min [Minute-by-minute reporter dons anorak] Possession
stats: Barcelona 73%-27% Celtic. They've had nearly 600 passes to
Celtic's 117.

62 min Celtic sub: Commons on, Brown off. "When you say 'as you were' with regards to Barcelona's insistent probing and general anal retentiveness as far as ball possession is concerned, is there a criticism there (implicit)?" asks Ian Copestake, opening up a gigantic can of worms. "Do do you take joy from it? Just curious." Personally I'm not one of those Barcelona-baiters. I love watching them play. But, yes, I would like them to mix it up a little bit more.

64 min Another two-on-two for Celtic; another near-miss for Barcelona. Mascherano tries and fails to block off Commons down the touchline, but the Celtic sub is unable to find Hooper with his cross. Barcelona are still dominating here, mind ...

66 min A half-paced Messi thruster squirms into Forster's arms. A minute later the keeper is called on again to save from Iniesta. The Celtic fans are in good voice singing - I think - Fields of Athenry, but their team is tiring.

68 min And still it continues. The pressing, the waiting: tension, torture. "Where was Song (Barca's only nominal holding midfielder) in that 2 v 2 Celtic counter-attack which Wanyama fluffed!?" asks SB Tang. "It was left to poor Xavi to hare back to support the two exposed Barca centre-backs. The man's got enough on his mind, what with his symphony orchestra conducting duties and all." Defensive duties have never been Song's strong point.

69 min Save from Forster! Perhaps his best of the night - Alexis's cross, Messi sliding across the six-yard line (possibly offside), the Celtic keeper hurling his body in the way to block. They couldn't hang on here, could they?

72 minCynical from Mascherano, who realising his team are short at the back, chops down Forrest. That's a yellow card. This Barcelona defence, which is admittedly missing its first-choice centre-halves and Busquets to protect it, is as rickety as a very rickety rickshaw going over a very rickety bridge.

73 min Barca! Barca! chant the fans. Another save from Forster. Meanwhile Dave Konopka emails in: "I love how SB Tang apparently thinks that Song 'holds' or otherwise plays defense. As a loyal Arsenal fan, I can tell you with absolute certainty that three things will happen whenever Alexandre Song plays. 1) He will play at least one incredibly incisive pass. 2) He will never be in position to break up a counter-attack. 3) He will commit a lot of fouls. This is why Arsenal are playing better defensively after selling Song, even if Arteta is far from a prototypical defensive midfielder."

75 min The biggest man on the pitch saves from the smallest! After more Barcelona passing, Iniesta plays a wonderful scooped lob into the unmarked Messi's path - the Argentine's header is palmed up in the air by Forster and bounces just wide of the post!

76 mins Barcelona sub: Pedro off, Tello on. Celtic sub: Mulgrew off, Kayal on.

78 min Yellow card Adriano for hacking down Ledley. "Come on celtic u can do it!" cries David Blackburn speaking, I suspect, for a great many of you.

80 min Barcelona sub: Pedro off, Villa on. Can Celtic survive? The odds are about 50/50 they will according to Betfair ... and what a result it would be if they could.

82 min Superb tackle from Ambrose, who takes the ball off the excellent Iniesta's feet. The corner, once again, comes to nothing - but from the resulting play Song is closing in on a header when Wangyama clears.

84 min A delay in play - and plenty of whistles - as Wanyama goes down with cramp. Celtic will be down to 10 men for the time being while he is treated. Incidentally Xavi has made 148 passes so far, with a 92% success rate.

85 min This is desperate, backs-to-the-wall stuff here, but
Celtic are hanging on. There's some lovely interplay between Villa and
Messi but Forster is alert to the danger. Meanwhile Wanyama is back on.

87 min Xavi, uncharacteristically, screws a shot wide. Three minutes now. Can they hold on?

88 min Celtic are playing with a back six here, but still they
survive. After a succession of taps, feints and short passes, Adriano
launches one into row Z. Then Alba, five yards from goal but on the
byline is tackled at the death. Celtic supporters are getting
boisterous now - they're singing "Celtic we love you!" Too soon?

90 min Now Villa hits the post from about 15 yards after more
superb work from Iniesta. So close. Meanwhile Daniel Finucane writes:
"Your explanation of Barca's shaky D was a tad rickety itself. Barca
are also missing their first-choice full backs, Alves and Abidal."
Fair point, Daniel.

90+1 min We'll be having four minutes of injury time. Surely
there'll be one more Barcelona chance?

90+2 min Huge cheers from the Celtic fans as Alexis allows a
pass to go out for a goal kick. Meanwhile Colin Owens writes: "I've
never had a bet come good with a late winner! Please don't let it
happen to me tonight. If Barca nick it the winnings will lie heavy in
my pockets...btw Wanyama is immense. How can his brother have a
champions league medal and Victor plays Ross County for a living?"

GOAL! Barcelona 2-1 Celtic (Alba 90+3) No. No. No. No. No. In the very last minute, Alexis cross evades everyone before Alba at the back stick beats James Forrest and bundles it home. Barcelona deserve it based on possession and skill; Celtic don't based on their heart and desire and everything else they brought to this game.

FULL-TIME "That's the sound of a million breaking hearts,"
suggests Matt Dony, not unreasonably. What an unexpected treat that
game was - and Celtic must be completely gutted. They applaud their
fans before trudging off, heads bowed. Still, they remain in second
place in the group and, with two home games to come, remain in the box
seat. Thanks for all your many emails and sorry I couldn't use them
all. Cheers, Sean.