Alcacer scores twice and Ramos - booed by home crowd - heads in
Sub Bartra adds fourth in second half
Vokes heads in late consolation for Wales
First Wales game at Principality Stadium since 2011
Bale misses match with groin injury
Wolves' Jonny comes on for Spain debut
Live commentary on BBC Radio 5 live
Israel 0-1 Scotland
Scotland have taken the lead over Israel.
Charlie Mulgrew slammed the ball high into the top corner from the spot after Steven Naismith was awarded a penalty for a push.
You can follow that match here.
Image source, ReutersWales 0-2 Spain
Suso has space to run into down the right and he tries to whip an early ball into the box for Alvaro Morata.
Chris Gunter does well to cut it out but concedes a corner.
Wales 0-2 Spain
Dafydd Pritchard
BBC Sport Wales at the Principality Stadium
It's one thing to be outplayed and outpassed by Spain, quite another to leave an aerial threat like Sergio Ramos totally unmarked to head in from a free-kick.
That goal rather took the wind out of the sails of the Wales fans here, though they were at least momentarily excited by Harry Wilson's audacious free-kick attempt.
Image source, Getty Images#bbcfootball
Andy Mac: Just found out Williams is back for Wales. 0-2...
Wales 0-2 Spain
Not a great start for Wales, but what have you made of the players so far?
You can rate them out of 10 here.
Image source, .Wales 0-2 Spain
Harry Wilson fancies himself to score from this...
He steps up, curls it towards the top corner but just gets too much on it and it flies over the crossbar.
Think David de Gea would have had it covered anyway.
Wales 0-2 Spain
Ashley Williams intercepts a slip inside from Alvaro Morata and frees up Connor Roberts.
Roberts plays it down the line for Harry Wilson. The Derby loannee skips inside and wins a free-kick as he's brought down by Sergio Ramos.
Excellent play.
Wales 0-2 Spain
Danny Gabbidon
Former Wales defender on BBC Radio 5 Live
It does not get any easier than that.
The Spain players are queuing up, Sergio Ramos is fantastic in the air and heads it back across Wayne Hennessey.
That is poor organisation, Ashley Williams is not picking anyone up, Alvaro Morata was free, there was Raul Albiol behind him too.
Sergio Ramos
Awful defending! What are Wales thinking?
Suso curls in the free-kick and Sergio Ramos is left unmarked to head it in comfortably inside the bottom corner.
Easy for the Spanish captain. And now Wales have a mountain to climb.
Image source, ReutersWales 0-1 Spain
Alvaro Morata tries to break forward through the middle but he's held back by Chris Gunter and the Welshman receives a booking for it.
Dani Caballos and Suso are lining up to take it.
Wales 0-1 Spain
John Southall
BBC Radio 5 live football reporter
The Spanish commentator sitting behind me almost took off when Paco Alcacer scored. Imagine what he’d be like in a competitive match? Very excitable!
Tough now for Wales.
Image source, Getty ImagesWales 0-1 Spain
Spain are starting to spray passes around the pitch. This time, one is over hit and it sails over Gaya's head and out for a goalkick.
Wales are desperate to keep the ball.
Wales 0-1 Spain
Danny Gabbidon
Former Wales defender on BBC Radio 5 Live
It is so difficult tactically when you are playing against Spain.
If one or two players only go for the press, then they can play through you. If you sit off then they can still pick you apart.
When you do not have the ball, you have to get it right tactically.
Wales 0-1 Spain
Alvaro Morata makes a darting run down the left but his cross is headed out for a corner by Declan John.
Image source, PAWales 0-1 Spain
Dafydd Pritchard
BBC Sport Wales at the Principality Stadium
When you consider Spain thrashed World Cup runners-up Croatia 6-0 last month, you do worry what kind of score they might rack up here given their total domination of these opening exchanges.
Wales 0-1 Spain
Harry Wilson, making his fourth start for Wales this evening, has not had a look-in yet. Sam Vokes and Aaron Ramsey are chasing shadows up front at the moment.
Spain just starting to settle.
Wales 0-1 Spain
Aaron Ramsey hassles Sergio Ramos, forcing him to turn back towards his goal, but gives away a free-kick.
Ethan Ampadu then catches the centre-back moments later and Ramos wins another free-kick in midfield.
Image source, ReutersWales 0-1 Spain
Danny Gabbidon
Former Wales defender on BBC Radio 5 Live
A wonderful finish from Paco Alcacer.
He gets too much time in the 18-yard box and whips it into the top corner.
Wayne Hennessey had no chance.
Image source, ReutersPaco Alcacer
Wayne Hennessey punches a cross clear but it comes straight back to Paco Alcacer, who makes no mistake and slots it into the top corner.
Not a great start by Wales.
Image source, Getty ImagesWales 0-0 Spain
Cesar Azpilicueta slips it through for team-mate Alvaro Morata. He gets into the box far too easily but the angle is tight and his low shot dribbles into the hands of Wayne Hennessey.
Aaron Ramsey then wins the ball in midfield and tries to play it on towards Sam Vokes but it's intercepted just in time.