Alaves, aside from that very dodgy first five minutes they had in the second half, are dealing with them, though.

Barca get another free-kick, left of centre. Again it's Messi to take. He tries to curl it round the wall, but it does not bend enough.

Lionel Messi is immediately on free-kick duties; playing over an outswinger from the left that Edgar - denied by the linesman's flag at the other end a moment ago - heads away. Barcelona are totting up the corners here...

Messi is on for Denis Suarez.

Alaves, after that big flurry of excitement, have regained their shape of the first half. Neymar goes on a run across the face of the area, but there's no way through. Arda Turan delivers a cros from the right, but it is cleared. Lionel Messi is getting ready to come on. We have half-an-hour to play, and this game is set up very nicely now.

Who will be your La Liga surprise guys this season?

Andy White: Rumour has it that some Welshman at Real Madrid is quite useful. His name is Gareth .... not sure of his surname....

To the other end, and Barcelona work the ball down the right... Paco Alcacer gets in front of his marker at the near post, and flicks a boot to turn his effort just beyond the far stick. Different game this, now. Caution has left us.

But wait! Alaves have the ball in the net. Edgar gets between defenders and goalkeeper to slot in a free-kick from eight yards, but he has made the run a fraction too early, and is correctly flagged offside.

Now Neymar goes on a run and whips a 20-yard shot just over the bar. And Lionel Messi starts warming up. The pressure is building...

Good grief. Alaves have gone to pieces here. Neymar swings over another corner, the ball drops to Mathieu 10 yards out - and the France defender has time to bring the ball down and blast at goal - he must score. No! It's wide. Gasps of disbelief all around the stadium.

Alaves last won at the Nou Camp in 2000. They are 45 minutes away from ending that wait. For now, Lionel Messi and Luis Suarez remain on the bench, and Neymar and Paco Alcacer lead the search for an equaliser. 

Almost three times as many passes by Barcelona as by Alaves in that first half - but the two sides are level in terms of shots on target. There's only one stat that matters, of course, and the visitors have that in their favour at halfway.

That was a first half that revealed its drama slowly. At first, there was little to get excited about. Then it became a case of wondering how long Alaves could hold off the Barcelona threat. Then the visitors took the lead, with a goal from Deyverson. Now the question arises: How long before we see Messi and Suarez introduced from the bench? The home crowd at the Nou Camp are grumbling as the players head for the dressing room.

Barcelona's urgency grows. Arda Turan nods down a cross into the penalty area. Ivan Rakitic turns into space 13 yards from goal; it's a great chance. He lashes the shot wide. And that is half-time.

For most of the first half, the question was: Can Alaves get to half-time level? Now, they will be down on themselves if they do not get there with a lead. They have played the first 44 minutes of this match just about note perfect.

Barcelona should draw level within seconds. Alaves switch off to let Neymar get on to the end of a cross, but the unmarked Brazilian heads wide from seven yards. A let off.

And we're into the final 10 minutes of the half. Barcelona pressing, probing, looking for the gap to exploit. Alaves are giving them next to nothing. The muted chanting from the crowd sounds like low thunder.

Image source, EPA

A moment or so later, another Barcelona free-kick. Neymar tries to catch out goalkeeper Pacheco at the near post, but shanks it into the rough.