IT IS ALL OVER! Celtic beat Barcelona. A stunning win for the underdogs. Absolutely stunning win this for Celtic. No more than they deserve. Magnificent from the Scottish champions.
Celtic out on their feet here, but they have a goal-kick as Forster hammers the ball long down the park.
GOAL! Messi scores for Barcelona from close range after a terrific save by Forster. Celtic need to see through a few more minutes.
We are into four minutes of time added on.
Forster will hammer the ball long here. Real Madrid the only other team to beat Barcelona this season. Astonishing stuff.
Villa sees a shot deflect behind for a goalkick to Celtic. Almost into injury time.
Mascherano seemed to have fouled Watt as he dashed through the middle. Referee said no. Looked to be the wrong decision.
Mulgrew with a stunning challenge on Fabregas out wide.
Barca look utterly shocked as Forster thumps the goalkick straight out of play.
Pedro's header blocked by Wilson from Messi's cross before Villa lifts a shot miles over. Celtic almost over the line here.
GOAL! Watt races through to smash the ball beyond Alves and Celtic lead 2-0. A brilliant finish by the teenager.
Messi with the dipping free-kick, but Forster is across to make the save. Brilliant save.
Ambrose blocks an Alba shot, but he clips Iniesta late and the visiting side will have a free-kick 25 yard from goal. Real chance here.
Mascherano wins the ball from Tony Watt. Excellent tackle by the Barca defender. Mulgrew with a clearance.
Samaras departs the scene to be replaced by Beram Kayal. Celtic hope fresh legs can see them through to the end here.
Alba sees a shot deflect off Commons before Villa knocks a shot over the bar. Celtic can make a change here.
Rain continues to lash down as Ledley wins the ball from Messi. Iniesta then lifts the ball over the bar from distance.
Celtic doing well to block a few crosses before Wanyama wins the ball from Fabregas. Samaras then wins a foul on the edge of his own box after being fouled by Alves.
Alves needing treatment for a head knock before Iniesta see the ball deflect into the path of Forster.
Celtic also make a change as young striker Tony Watt takes over from Lustig for Celtic.
Fabregas takes over from Song for Barca, who should have been sent off moments earlier.
Pique takes over from Bartra as Barcelona look to ring the changes.
Jordi Alba slides the ball into the path of Messi, whose shot is clawed out by Forster. Brilliant save by the big goalkeeper.
Song somehow survives a sending off for a late challenge on Miku. Should have been off the park having already been booked.
Villa has replaced Alexis for the visiting side. Commons knocks the ball behind for a corner from the Alves cross.
Commons with a long ball up the park for Samaras, but Barca can get the ball out from deep.
Jordi Alba has been booked. Seemed to be for a foul on Commons.
Wanyama makes a strong surge up the park, but the cross isn't the best from inside the Barca box. Ball flies straight out of play.
Bartra makes a last-ditch tackle to win the ball from Mulgrew as he prepared to pull the trigger. Celtic almost in for the second goal.
Samaras back to Forster before Lustig is taken out of the action late by Alexis.
Lusting with the throw-in for Celtic. Back to Ambrose. Forster hammers it long. Wanyama again offside.
Benfica lead 1-0 against Spartak as Alexis fires a shot at goal. Brilliant save by Forster before he blocks another effort seconds later. Celtic living dangerously here.
Alba sees a cross deflect safely into the arms of Forster as Celtic's rearguard continues to hold firm here.
An offside flag is rasied against Wanyama, who doesn't need to be pressing so far up the park.
Mulgrew dinks the ball in. Lustig gets a header at goal, but a comfortable enough stop from Valdes in the Barca goal.
Mulgrew knocks the ball off Alves. And Celtic will have another corner here to be taken by Commons.
Messi fires a shot at goal from distance. Ball was heading into the corner, but Forster is again equal to the the task.
Mulgrew gets in a tangle with Ledley. Just fails to keep it in play. This Barca side keep coming and coming as Alves knocks it wide.
Xavi with another testing cross, but this time Ambrose on hand before Matthews makes a telling tackle. He is playing superbly tonight.
Matthews makes a stunning tackle to win the ball from Alves. A super challenge by Matthews.
Pedro heads over the bar from Alves's cross. Not a bad attempt, but just wide of the home goal.
Another superb ball across the face of goal by Alves, but the cross skips across the face of goal. Another goalkick to Celtic.
Barca content to go backwards. Commons forced to race back to challenge Iniesta.
Alves sees a cross charged down by Matthews as the loose ball breaks kindly to Forster in the Celtic goal.
Mascherano tries to slide in a long ball with Pedro on the charge, but the ball has just too much on it. Goalkick to Celtic.
Ball flies out of play, and Celtic are again on the backfoot here as Iniesta collects the loose ball.
Celtic get this second half off and running.
There goes the whistle for the break! Celtic lead Barcelona at the break 1-0. All to play for in the second period.
Iniesta can't control a loose ball and Celtic will have a throw-in. Where else? Deep in their own half.
Celtic have a throw-in at their halfway line. Celtic trying to head for the break holding this lead here.
On we go again as Ambrose clears. Samaras clips Bartra at the back. Barca just keeping the ball so well again before it runs out of play.
Miku has been booked for a late challenge on Iniesta. Barca again opt to pass the ball short rather than throw it in to the danger area. Forster off his line to knock it away.
Alba sends the ball across the face of goal. Forster gets a hand to it before Celtic scramble the loose ball away.
Xavi tries to pick out the run of Alves. Lovely ball, but Alves just fails to connect as the ball races through for a Celtic goalkick.
Alves knocks the ball deep into the Celtic box, but Commons is doing the covering work well to clear.
Brilliant touch by Mascherano to win the ball from Miku before Wilson takes out Pedro with a late challenge.
Alexis sees a header comes off a post the cross of Alves. Forster couldn't get across to keep that header out. Celtic get lucky. Brilliant effort by Alexis.
This is like a training ground session. Celtic having to defend as Wilson thumps away the cross of Alves.
Samaras brings the ball up a flank, but Barca in possession seconds later. Matthews closing down the space of Pedro.
Alexis slides the ball to Alba, but nobody is there to finish in the middle. Teriffic play by Alba. Celtic cut open.
Alves feed the ball to Xavi but he thumps the ball over the bar. Well over really.
Iniesta on the ball for Barca. Celtic pressing the ball as much as possible against this exciting visiting side. Messi with another lovely pass. Looking for those one-twos.
Barca with 67 percent possession at the moment which tells you just how this match is working out at the moment. Ledley clears the ball from Alba's cutback.
Alves trying to tee up Messi, but Celtic again defend. Messi then cracks a shot off the bar from Iniesta's pass. So unfortunate. Delightful stuff from Barca. But replays show that Forster got a touch on the ball to make the save.
Celtic certainly getting up the park as much as Barca will allow them here. So easy on the eye the Catalan giants.
Commons brings the ball up the park. Brilliant ball by Matthews into the box, but Samaras just fails to connect as Valdes comes out to smother.
Barca camping on the edge of that Celtic box before Alves sees a drive blocked by Mulgrew. Decent defending by Celtic.
Song tries to slip in Messi, but Commons hammers the ball long down the park. Celtic trying to remain vilgilant in defence. Easier said than done.
Celtic Park is alive to the evening. That was a stunning effort from Wanyama, who is again impressing on this stage. Celtic ahead with their first chance of the night.
GOAL! Wanyama rises to head into the net from Mulgrew's corner. Brilliant finish from the Kenyan midifelder. Barca nowhere to be seen in defence.
Alexis challenges Ambrose as the ball came back out to him. Celtic have their first corner of the night here.
Some outstanding charging play by Wanyama in winning the ball before earning Celtic a throw-in deep in the Barca half.
Song can't afford to be too late with another challenge having already been booked. Jordi Alba hammers the ball long down the park. No nonsense stuff.
Barca always seem to have another pass on here. Celtic being forced to defend manfully here. Late tackle by Song on Miku.
Lusting comes across to win the ball from Alexis. Some fine play involving Alexis and Pedro. Some terrific play by Barca it must be said going forward.
Celtic being forced back by the class of this Barca side, who continue to dominate possession. Wilson makes a fine challenge to win the ball in the centre of his box.
Iniesta tries his luck, but Celtic have enough bodies back before Iniesta keeps the ball in play to deny Celtic a goalkick.
Valdes comes off his line to punch clear the throw-in from Adams. Samaras against caught narrowly offside.
Song takes Miku out of the play, and he has been booked for that challenge. Celtic trying to get bodies up the park.
Alexis takes a tumble under pressure from Lustig. Just gets the tackle in. Could have conceded a penalty there. Got it just right.
Wanyama wins the ball in the centre of the park before rolling the ball back to Forster. Samaras caught offside seconds later.
Commons chops down Song with a late challenge. No booking as yet. Referee trying to let the game flow here.
Alexis makes a strong dart into the box, but Forster is quickly off his line to collect the loose ball.
Commons wins the ball from Alba. His long ball is just too long for Miku as Valdes comes off his line to collect.
Alba slides the ball into the path of Messi, but he lifts the ball over the target. Some lovely one-two stuff from the visiting side. Brilliant play.
Alexis nudges a loose ball towards goal from the shot by Xavi, but Forster was on hand to save. Poor clearing header by Mulgrew it must be said.
Celtic can't find the final pass into the box as Mascherano comes across to win the ball and Barca can again break. Late tackle by Commons on Iniesta.
Mascherano takes out Samaras with a late challenge. And Celtic will have a free-kick here from 40 yards out. Chance to throw in this free-kick.
Song winning the ball from Samaras with a strong challenge. Barca again collect the loose ball in the centre of the park.
Alves slides the ball through to Pedro, but strong defending by Wilson to shield the ball out of play. Celtic have a goalkick.
Barca straight into their stride here as you would expect. Keeping the ball with some ease before Jordi Alba fails to keep the ball in play out wide. Celtic trying to get in possesion. Easier said than done.
Barcelona get the evening off and running here.
Teams out and we are almost ready to go. Celtic manager Neil Lennon relishing the atmosphere. Celtic do their huddle. What an atmosphere in the ground.
The Celtic fans getting ready for this match. The sound of You'll Never Walk Alone rings out. 60,000 shoehorned into Parkhead for this one. Not sure if it will frighten Barca, but certainly an impressive evening in the driving rain of Glasgow's East End.
So here is the betting for this evening's match in case you fancy a tickle. Not a huge surprise to learn that Barcelona are strong favourites to win this match: Celtic 9/1 Draw 9/2 Barcelona 3/10
Barcelona have won seven and lost just one of their last nine Champions League away games, keeping six clean sheets in that run. Barcelona have won 21 and lost just two of their last 29 Champions League games with both defeats being suffered in England.
Celtic have won just three of their last 11 European matches on home soil - won three, drawn five five and lost three. Celtic have only lost five of 59 home games in the European Cup, but two of those were against Barcelona. The Scottish champions have only lost two at home in the Champions League and both were against Barcelona.
Marc Bartra is back in central defence alongside Javier Mascherano for Barca. Lionel Messi is seeking his first goal for the visiting side since he became a father for the first time last Friday.
Barcelona coach Tito Vilanova: "This is our most important game in the group stage because we need to win it to qualify, regardless of the result in the other match. We'll be able to rest players once we have qualified."
Celtic manager Neil Lennon: "If you're open against Barcelona, they will beat you convincingly by just picking you off. They've got so much quality and so much pace, and they know how to attack. They are the best passing team in the world, and you are going to be chasing the ball against them for long periods whatever you do. I'm going to concentrate on what we're going to do. I've looked back at the first game and I remain proud of my players for the way they performed on the night."
Gerard Pique starts on the bench after recovering from a foot injury, but Alex Song makes it. Alexis Sanchez starts for the visiting side, but Adriano misses out. Sergio Busquets is suspended. Lionel Messi needed treatment for a knock on his knee at the weekend, but is fit and starts the match.
Celtic manager Neil Lennon hands Georgios Samaras a start to support Miku in attack. It his first appearance since he suffered an ankle injury in the 2-1 loss to Barcelona in the Camp Nou a fortnight ago, a match in which he scored. Gary Hooper is injured with a hamstring strain while Emilio Izaguirre suffered a hamstring injury at Dundee United on Sunday and will be sidelined for six weeks. Celtic are also without skipper Scott Brown (virus).
Teams: Celtic: Forster; Lustig, Ambrose, Wilson, Matthews; Commons, Wanyama, Ledley, Mulgrew; Miku, Samaras..subs: Załuska, Fraser, McCourt, Herron, Kayal, McGeouch, Watt.////Barcelona: Valdés, Alves, Bartra, Mascherano, Alba, Xavi, Song, Iniesta, Alexis, Messi, Pedro..subs: Pinto, Piqué, Montoya, Fàbregas, Dos Santos, Villa, Tello.
Good evening and welcome to LIVE coverage of Celtic against Barcelona in Champions League Group G at Celtic Park. Teams coming right up for you.