Three of Real's four shots have been outside the box. And three have been on target.

Barcelona have had 13 efforts, 12 inside the box and four on target.

A good spell for Real Sociedad.

Mikel Merino has a shot saved from outside the box and then Willian Jose slices an effort well wide.

Barca make a double switch. Antoine Griezmann and Sergio Busquets are replaced by Francisco Trincao and Carles Alena

Real Sociedad bring on Alexander Isak for Portu. The Swede has struggled a bit this season.

It's cleared by Antoine Griezmann and the referee spotted a foul so Barca have a free out.

Free-kick to Real Soc on the wing. Portu to take.

Alexander Isak is getting ready for Real Sociedad.

Mufti Zakariyya Mohamed Sunusi PhD: A strong first half from Barcelona? What a night... It seems barca players are getting familiar with each other

Sulaimon Adelekan: What a first half at Camp nou. Barcelona have turned this around but they still have work to do in the second half to put this game to bed.

Right, don't hate me - I forgot to open the Twitter tab with the hashtag. It's open now and I'm ready for your thoughts...

The TV cameras have shown several replays of that Antoine Griezmann sitter. Literally just had to slide into an empty net but it hit the wrong part of his boot.

Real Sociedad took an age to bring Adnan Januzaj off. They were playing with 10 men for a few minutes.

Ander Barrenetxea and Roberto Navarro replace the ex-Sunderland man and Ander Guevara.

Now Antoine Griezmann is played in one on one but is denied by the keeper.

How has Antoine Griezmann missed? He slides in to put a Jordi Alba cross into an empty net... but somehow kicks the ball sideways into the keeper's arms.

Maybe I've done Adnan Januzaj a disservice there, he's gone down injured and needs treatment.

Great by Adnan Januzaj... and then poor.

He shows a fine first touch and turn of pace to beat Frenkie de Jong but then his cross is beyond everyone.

A good Real move as Portu finds Igor Zubeldia but the ball won't land low enough for him to get a shot in.

A good run by Lionel Messi from the halfway line but it ends in a weak shot from just inside the box which is saved easily.

That's the first save Alex Remiro has made.

Real straight on the attack and Ronald Araujo does well to stop Adnan Januzaj skipping into the box. It was a bit of a push but the ref wasn't interested.

The second half begins.

As things stand Barcelona would only be six points off top.

Real Sociedad would drop to second behind Atletico Madrid on goal difference (La Liga is decided by head to head but only after teams play each other twice).