Last Updated: 10/12/11 10:54pm
ALL OVER. Huge result for Barcelona but what a disappointing night for Madrid. They made the dream start and should have built on it but allowed the visitors to come back at them and clinch the points. It's game on in La Liga now. Thanks for joining me and check back soon for reports and reaction.
Free-kick for Madrid and there's a set-to in the Barca area as the clock ticks down. Ronaldo lines up the dead-ball but again he hammers it into the wall. Sums up the Portuguese star's night.
The Bernabeu is emptying now after a famous win for Barcelona. What a frustrating night for the hosts.
Just a game of keepball now for the visitors. Little noise in the stadium save for the 500 travelling fans from Catalonia.
Another great run into the home box by Iniesta. He tries to pull it back for Alves but Pepe denies him.
What a scramble in the Madrid box after an awful howler by Pepe. Iniesta drives his shot at Casillas and then pounces on the rebound but somehow it ends up in the arms of the home skipper.
Great save by Valdes to deny Kaka. The keeper did just enough to turn the Brazilian's effort away for a corner.
Another change for Barca and Sanchez makes way for David Villa who has found himself down the pecking order of late.
Madrid are still hammering on the door looking for a way back but it looks like the two sides are going to finish the evening joint top of La Liga.
Free header for Xavi after another great run and cross by Alves but the midfielder puts it just wide.
Ronaldo runs at the Barca defence to try and make up for his miss earlier but he can't release Benzema.
Ramos booked for awful foul on Messi. The Argentine had to jump to get out of the way of that lunge.
Goal Barca. And that's got to be game over. Superb move sees Alves swing over a right-footed cross and Fabregas is there to score with a diving header. Brilliant counter-attack by the visitors.
What a miss by Ronaldo. On a plate for him by Alonso but he heads it wide from just six yards out. The former Manchester United man is having a shocker tonight.
Another change for Madrid as Diarra makes way for Khedira. The former Portsmouth midfielder had just been booked so can't afford another moment of indiscretion.
Good play from Benzema to force a corner. Alonso swings the ball in but the visitors are able to clear.
The Bernabeu is shell-shocked after that Barca goal. There's activity on the Madrid bench as Jose Mourinho prepares a response.
BARCA AHEAD: A freak goal for Xavi as it deflects off Marcelo and beyond the desperate reach of Casillas. The ball just span back and went in off the post.
Another foul, this time on Pepe, gives Ronaldo another dead ball chance. He hits the target as it bounces in front of Valdes but the Barca keeper hangs on well.
More of your emails and Mark says: "Good game but hate to see the theatrics from Madrid. They are doing everything to get Messi sent off. This is why they are hated and Barca loved." Gaz adds: "Great game, sendings off to come for sure, I'm going Real 3-1, Ronaldo double."
Update from Sky Bet and they now make Barcelona favourites at 7/4 with Madrid drifting to 2/1.The draw's available at 6/4. Don't want to crow but I get on the 7/1 offered for Benzema to net the first goal. Happy days!
Thanks for all your messages. Not sure I'll get through them all. Will says: "Wow what a game so far. Real Madrid have decided to play football and it's paying off. I can see them snatching this game Can't wait for the second half." Chris adds: "Interesting game so far, Barca seem to have found their feet after that edgy start. I predict a 2-2 draw." while Paul remarks: "This is an incredible game and I can see we will have a sending off. Want Madrid to win with Ronaldo getting 2 goals in the second half."
What a great first half that was. Great start for Madrid but Barca have come right into things. Join me in 15 minutes for more breathless action
Messi could easily have been sent-off there for that challenge on Alonso. The ref thought about producing a second yellow but then changed his mind. Big call that one.
I'm looking forward to receiving your comments about the first half via email to email@example.com. I'll try to publish as many as I can.
Sanchez is walking a tightrope here considering he's already in the book. He's protesting heavily at every challenge.
Madrid seem content to play it long and look to hit Barca at pace. They need to be more accurate for that tactic to pay off though.
Now Sanchez is rolling around after being clipped by Pepe. Didn't know AK47s were allowed into the stadium. Get on with the game please.
Naughty challenge by Alves on Alonso. He left his foot in there and is very lucky to escape a yellow card.
Barca now right back in it in every sense. The Bernabeu crowd has been silenced and the visitors are beginning to play the game their way.
EQUALISER FOR BARCA: Sanchez scores for the visitors after a great through ball from Messi. The Chilean had plenty to do but his strike was beyond the reach of Casillas. Game on here.
Dani Alves is rolling around like he's been felled by Mike Tyson after a clash with Marcelo. Nothing in that for me though. Let's get on with this thrilling game.
Great chance for Ronaldo but he slices it horribly. That should have been 2-0 - and a pass to di Maria who was in the clear would have made certain of it.
It's clearly a tactical ploy from Mourinho to pressure Valdes and threaten his distribution. The Barca keeper looks shocking with the ball at his feet.
Diarra fells Fabregas on the edge of the Madrid area. Xavi and Messi stand over the free-kick and the former's shot is beaten away by Casillas.
Iniesta tries to release Alexis with a neat through ball but Pepe is on hand to snuff out the danger.
No sooner do I write that than Ronaldo runs at the Barcelona defence and lets fly from 20 yards but his effort is beaten away by an uncertain Valdes.
Another awful clearance by Valdes and Alonso tries to punish him from long range but he's off target.
Good cross by di Maria which is met powerfully by Benzema but Valdes gets down well to save at his near post.
Alexis is waving an imaginary card at Coentrao after a hefty challenge out wide but the referee keeps his cards in his pocket. I hate to see players doing that - but it was a hefty challenge.
Mistake by Ramos and Messi is in on goal but Casillas pulls off an outstanding save with his right hand to deny the Argentine. What an opening to this contest. It's not disappointed so far.
Barca are rocking and Madrid are pressing them all over the pitch. Valdes receives another back pass and gets rid of it hurredly. I'm struggling to get my breath back after that dramatic opener.
INCREDIBLE START. Goal for Madrid in the first minute after a horrible mistake from Valdes. His pass is intercepted and Benzema is able to prod it home from inside the six-yard box. What drama.
The teams are out and the rain looks like it's played havoc with Carlos Puyol's hair which has turned into a frizz-bomb - oh wait a minute...
Kick-off just moments away. Last couple of your pre-match predictions and many of you are leaning towards a Madrid win including Brett and Raj.
It's a pretty miserable night in the Spanish capital - but that should make for a slick surface and sets us up for a cracking Clasico. Just 15 minutes to kick-off now.
Marcus is shocked by Barca's decision to leave Villa on the bench and says: "I think Madrid could win this quite comfortably. They have been the best in the league upto now and Barca have looked like slipping up. Also No Villa in the biggest game of the season? I think we could be seeing him in the premier league quite soon. 3-1 Madrid Win."
Interesting move from Sky Bet pre-match. They've price-boosted Messi to be first goalscorer from 4/1 to 5/1. Think I'll have myself a bit of that.
Not had many predicting a draw but Terry thinks it'll finish 1-1. Kevin expects a busy night for the officials with a couple of red cards likely to be dished out.
So no David Villa in Barca's starting line-up while Jose Mourinho seems ready to go on the attack with his selection.
More predictions. Conor and Eddie fancy Madrid to come out on top but Jordan - who will be following through the Score Centre so thanks mate - thinks Barca will prevail thanks to Messi.
News of the teams is coming through. Real Madrid Casilas, Lass, Ramos, Pepe, Marcelo, Alonso, Khedira, Ozil, Di Maria, Benzema, Ronaldo. Barca Valdes; Alves, Pique, Puyol, Abidal; Xavi, Busquets, Iniesta; Messi, Fabregas, Alexis
Please keep your pre-match predictions coming into me firstname.lastname@example.org. Mihir goes for a 2-1 home win while Andrew thinks the visitors will come out on top. Ashton on the other hand can't see beyond a home win and thinks Madrid will run out 3-1 victors.
Our friends at Sky Bet make Madrid slight favourites tonight at 6/4 while the visitors are priced at 7/4. The draw is 12/5. You can follow updates via @skybet on Twitter.
More predictions and Cian says: "I am a huge Barcelona fan and this La Liga table is looking tight. If Barcelona win tonight they go top. It is a super tough game here as always. I'll go for a 2-3 win for Barcelona."
Lucky old Mark says: "Just happen to be in Barcelona this weekend the bar I'm in are running a sweep stake so if it's 3:3 I'll be very happy :)" I'll keep my fingers crossed for you Mark - and enjoy Las Ramblas!
A couple more predictions for you. Both Dan and Oludare feel the hosts will come out on top and are expecting a big night from Cristiano Ronaldo.
One or two fascinating facts from our friends at Opta. Lionel Messi has scored in his last five visits to the Bernabeu while Madrid have had six players sent off in the last seven Clasicos.
Had the word from Andy May, my contact in the Bernabeu, that it could be a wet El Clasico with rain tumbling down in Madrid ahead of kick-off.
Dan has been in touch and predicts: "I think a 3-2 win for Barcelona with Messi, Xavi and Villa scoring for Barcelona and Ronaldo scoring twice for Real Madrid." Can't say I agree Dan. I've got a sneaky feeling for Madrid this time out.
Dion has also had his say and adds: "Real Madrid 1-1 Barcelona with Benzema scoring for Real Madrid and Messi for Barca."
Thanks for your predictions so far. Matt says: "As great as Madrid are, they seem to crumble in the big games and I can see Barca taking this 2-0 with a goal in each half." while Peter adds: "Real to win but the ref needs to be good - to stop Barca cheating."
Can't wait for this one to kick off. If you have any pre-match predictions then please email me - email@example.com