And the fourth duly arrives through the boot of Messi after another outstanding move. Suarez is again heavily involved, his backheel allowing Messi to pick his spot inside the area. This is starting to get very ugly for Valencia and Gary Neville. 

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Chances for Barca...lots of chances. Arda Turan,Messi, and then Messi again, all go close with efforts. You get the feeling that fourth goal is not far away.

Not sure what Gary Neville has said to his players at the interval but they've made a lively start to the new half. Barca defender Jeremy Mathieu concedes a corner but normal service is quickly restored as Gerard Pique goes close with a header that lands on the roof of the net.

Changes made by both teams at the start of the second half. Valencia bring on Ruben Vezo for Siqueira, while Iniesta is replaced by Sergi Roberto.

Prince Gyimah: Gary Neville won't last at Valencia.

Eggy: Just a shame he can't actually move the players magically by touching the screen to where they should be.

Sai Mann: Barca playing so well, great to watch. Sad for Gary Neville though.

The 10 men of Valencia get us back under way. Can Valencia keep the score down? Will Barca rub salt into Gary Neville's wounds?

Just the 72% possession from Barcelona. There is a second leg to come next week but unless Valencia start defending, they might as well scrap the return at the Mestalla.

Tom Fisk: Neville should have waited for the Celtic job. Pretty much guaranteed success, suits his character and probably available soon!

Thomas Neilly: Neville never managed a team - gets Valencia. Yet many mangers who have proved themselves would never get near the job.

Aron Nyagweya: Valencia looking ordinary and clueless. They should seriously consider hiring engineer Pellegrin next season.  

Not only are Valencia being out-played and losing heavily, they will have to play the second half with 10 men. This is turning into a disastrous night for Gary Neville.

Drama right at the end of the half. Valencia defender Shkodran Mustafi is shown a red card for taking out Lionel Messi who was the last man. Neymar steps up...and hits the post.

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So close to number four. And it's that Suarez-Messi combination again that unlocks the Valencia defence. Suarez is in the clear, he looks up and finds the run of the Argentine who hits the woodwork. 

A rare chance for Valencia. Daniel Parejo connects with the ball in the box but there's no composure and it flies over the bar and into the crowd. The visitors cannot wait for the half-time whistle.

Four shots, three goals. Barca have been utterly ruthless but that does not excuse Valencia's defensive frailties. It's been men against boys and the scary thing is there's another 50 minutes or so to go. The visitors have actually improved since conceding the third goal but Barca look as though they will score each time they venture past the half way line.

Gary Neville has responded to the third goal by making a change. Midfielder Danilo is replaced by France-born winger Sofiane Feghouli. His team is taking a real battering and half-time is still another 10 minutes or so away.

Another sumptious Barca move...another goal. Lionel Messi finishes from eight yards after Valencia's defence is carved wide open by a some wonderful one-touch passing. Neymar, who looked hurt in the opening stages after sliding off the pitch, has made a full recovery and played a big part in the goal.

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