The teams are already in - Gareth Bale starts with Cristiano Ronaldo, James Rodriguez and Javier Hernandez also up top. Karim Benzema isn't fit enough to make the squad, despite returning to training this week.

Real XI: Casillas, Arbeloa, Pepe, Ramos, Coentrao, Kroos, Isco, James, Ronaldo, Bale, Hernandez.

Valencia XI: Alves, Barragan, Mustafi, Otamendi, Gaya; Javi Fuego, Andre Gomes, Parejo, Feghouli, Piatti, Alcacer.

Spanish football writer Andy West at the Nou Camp

"Barca were well below their best today, but still thoroughly deserved winners. Real Sociedad defended well and can be happy with their performance, but after Neymar's header it was never in doubt. They march on."

That's yer lot. Barca are home and hosed.

Now we're off to Madrid. Can Real keep up by beating Valencia?

Gorka Elustondo is on for a Sociedad corner with Esteban Granero coming off. Surely too late for anybody to claim some kind of master stroke though.

Sociedad break the offside trap and Alfred Finnbogason, with all the goal to aim at, fires straight into Claudio Bravo's gloves.

Sums their day up, La Real.

Three minutes of stoppage time.

Three trophies for Barca? Top of the league, one foot in the Champions League final, and the Spanish Cup final to come against Athletic Bilbao on 30 May.

Spanish football writer Andy West at the Nou Camp

"Credit to Luis Enrique. Switching to four up front when you're leading by one in the final stages isn't something many managers would do, but it paid off as Pedro scored.

"And it's a popularly received goal. Pedro has had a tough season but he remains a well liked figure with Barca fans."

That seems to have wrapped it up. Barca are cruising now.

Look out Bayern. Pep Guardiola's side lost 1-0 at Augsburg earlier today. That's no kind of warm-up for what they need to be a 4-0 home victory to progress.

And it's almost three as Lionel Messi breaks clear on the counter - his low curled shot creeps wide of the post. He's not been at his best today.

Image source, Getty Images

What an impact the substitute has had. Just moments after coming on Pedro fires home in spectacular fashion.

Surely the points are safe now. Barca deserve it for that strike alone - a bicycle kick as the ball loops up in the area.

Here they come now - Lionel Messi plays in Neymar, there's a return pass and the first time Messi has had a clear sight on goal but his shot is weak. One of the easier saves Geronimo Rulli has had to make.

Spanish football writer Andy West at the Nou Camp

"Bringing on winger Pedro for midfielder Rafinha was an unexpected move from Luis Enrique, and Lionel Messi has dropped back into an attacking midfield position in what looks like a 4-2-1-3 formation. Very bold."

There are seven minutes to play here and twenty minutes to go before kick-off at the Bernabeu where Real Madrid take on Valencia at 19:00 BST.

As it stands Barca are going five points clear of Carlo Ancelotti's side. Will they hold on or look for a second?

Under 10 minutes to go and those changes are beginning to look good for La Real. This is the first sustained bit of possession they've had in this half - of which most was actually in Barca territory for a change - but it all comes loose with a poor long ball.

For Barca, Rafinha is off for Pedro.

Spanish football writer Andy West at the Nou Camp

"David Moyes is going for it, bringing on Alfred Finnbogason. The Icelandic striker became a bit of a figure of fun in Spain after waiting a very long time for his first goal after signing from Heerenveen last summer, but he's scored twice recently including last week.

"Now would be a good time to really make a mark. Good for Real Madrid, anyway."

If anything's going to light this game up it's the combination of Andres Iniesta and Lionel Messi.

Iniesta beats his man with that oh so subtle jink only he knows how to do, but Messi isn't holding up his part of the bargain. His pass towards Luis Suarez is loose and easily cleared by the Sociedad defence.

Ruben Pardo, that is just not nice. Neymar goes down under a wild challenge and it's a yellow card.

Another substitution from David Moyes - but Carlos Vela coming off? Unfit? Alfred Finnbogason is on in place of the Mexican.

Spanish football writer Andy West at the Nou Camp

"David Moyes has switched to a 4-4-2, with captain Xabi Prieto going up front alongside Vela, and the game has grown a bit scrappy. Barca are looking comfortable enough but they haven't raced away with the game as we might have expected when Neymar scored."

Sociedad change it up and Sergio Canales is off with the Uruguayan Chory Castro on in his place.

For Barca, Xavi trundles off to wide applause. One of his last games at the stadium. Anders Iniesta is on.

It flows like water. A cutting ball in from the right, cushioned on the chest by Xavi, Lionel Messi with perfect timing running on to it and striking first time...

But blocked again by the Sociedad defence. They've got to keep this up for 20 minutes yet, and find some way to score...