Peeep peeep peeeep! It's all over! Athletic have dumped Barcelona out of the Copa del Rey in the most dramatic of fashions!

Particularly after a second half in which Barça had the lion's share of the play and carved out two gilt-edged chances to score, it would, in truth, be flattering Athletic to say they were the better side tonight.

However, goalkeeper Unai Simón produced fine saves with his legs to keep out first Antoine Griezmann, then Lionel Messi, and with extra time seemingly looming, Iñaki Williams' angled header won it for the hosts - and blew the roof off San Mamés. 

It's a result that caps a miserable few days for Barça and, with Real Madrid also going out this evening, it means the Copa semi-finals will feature neither of Spain's 'big two' for the first time in a decade.

Athletic join Granada, Mirandés and Real Sociedad in the draw for the last four, which takes place tomorrow lunchtime. You'll be able to follow that live online with AS English, so be sure to join us!

That's all from me - thanks for reading.

One final chance for Barcelona. Semedo stands over a free-kick just inside the Athletic half, with pretty much everyone else packed inside the box. He hoofs it up into the area... and Simón comes out and gathers! That must surely be that!

Four minutes of time added on stand between us and extra time.

Ibai Gómez is on for Athletic, replacing Raúl García.

Straight away, Williams has a half-chance to punish Messi for his uncharacteristic profligacy, but he shoots wide when Dani García's cross finds him at the back post! It looked like Aduriz slightly got in Williams' way, in his defence.

Again Simón saves with his legs when for all the world it looks like Barcelona will score! Arthur's defence-splitting ball releases Messi into shooting space inside the box, but his low strike is kept out by the Athletic goalkeeper!

Griezmann exchanges passes with Messi before feeding it out wide to Alba... but it's blocked by Capa.

Barça then win it back, and...

Rakitic clips a ball into the box, but Núñez heads it clear. Back come Barcelona, but they can only play it about in front of a well-drilled, packed Athletic defence and, after probing for an opening for a good couple of minutes, are finally dispossessed.

Arthur is the latest Barcelona player to go into the book - I make it six in total now - for gently clothes-lining Aduriz as he tries to hold the striker off.

There's a chance for Williams... but he blasts it over! Aduriz heads it on for his forward colleague to run on to, but he can't keep his shot down from the right-hand side of the box.

Umtiti is on for the visibly struggling Piqué.

Athletic make their second change, Iker Muniain coming off for Aritz Aduriz. Overhead kick o'clock?

I neglected to tell you that Mikel Vesga was replaced by Mikel San José in the hosts' first change 10 minutes ago.

Piqué is limping majorly, and Samuel Umtiti is warming up over on the touchline.

...which is swung over to the back stick, but Núñez can't quite turn it goalwards and the ball goes behind. He feels he should have had a corner, but a Barça goal-kick is given.

Williams absolutely does Piqué for pace on the left wing, leaving the Barcelona defender with no choice but to haul the forward down, in a manner that wouldn't look out of place on the rugby field. Yellow card for Piqué, and a free-kick for Athletic...

Raúl García fires a speculative effort well off target. Athletic know they're second best at the moment.

Griezmann should score! De Jong lifts a lovely ball over the top for Roberto to carry the ball into the Athletic box, before looking up and cutting back for Griezmann on the penalty spot... but Simón saves with his legs! Barça's best chance of the night.

Barça make their second change, replacing Rakitic with Arthur.

De Jong flops to the turf under Capa's challenge in the box, but the referee firmly waves away Barcelona's penalty appeals.

Moments later, the Dutchman almost gets on the end of Alba's cross into the box, but Simón is out quickly to grab hold of the ball.

It's been a good few minutes for Barcelona.

Dani García brings down Messi in the left-hand channel, giving Barça a chance to swing it into the box. The midfielder earns a yellow card for his misdemeanour.

When the cross is delivered, Lenglet challenges Simón and the loose ball falls to Roberto, who fires against the post. Lenglet was offside, though, so it wouldn't have counted even if it had gone in.

Barcelona pop it about in front of the Athletic defence for a good little while, before the ball is fed to Messi in a yard or two of space on the edge of the box. When he's tackled, the loose ball falls to Griezmann to shoot - but he blazes well over!

Barcelona make their first change, replacing Ansu Fati with Antoine Griezmann. The former Real Sociedad forward gets the warm welcome he'd expect at the home of the Txuri-Urdin's fierce Basque rivals.

De Jong flops over the challenge of Unai Simón on the edge of the box after streaking down the middle of the Athletic defence and in on the on-rushing goalkeeper... and is deemed to have dived! Yellow card for the Dutchman.

Ter Stegen once again almost gets his side in trouble with an errant pass out from the back. He puts Rakitic under extreme pressure on the edge of his box, but the Croat escapes when Dani García is adjudged to have fouled him.

Vesga is shown a yellow card for a late tackle on Messi before the Argentine passed the ball to Fati.

Messi plays the ball to Fati on the edge of the box, but the youngster takes one touch too many and, by the time he has fed it on to Alba on the left, the full-back has drifted into an offside position.

Tonight's attendance of 49,154 is the highest Athletic Bilbao have had since moving into the new San Mamés in 2013.

It's all Barcelona possession for the first couple of minutes after the restart, until Fati feeds Messi and, in his attempts to run at the Athletic defence, the Argentine overhits his touch out of his body and allows the hosts to reclaim the ball.

Peeeeeep! We're back up and running in Bilbao.

No half-time changes for either side.

Peeep peeep peeeep!

No goals to speak of at half time, but that was an intense, very watchable first 45.

One minute of time added on.

Messi sets off on a mazy dribble towards the Athletic box, before finally being brought down by Yeray Álvarez. Free-kick on the edge of the area, yellow card for Yeray.

Messi takes... and plops it straight into the wall.

Williams is furious to be penalised for a foul on Lenglet after winning the ball back on the Barcelona byline, before the referee makes his way over to book Barça boss Quique Setién for speaking out of turn. He was unhappy about a challenge on Fati that wasn't punished, it appears.

Messi is shown a yellow card for a mischievous little challenge from behind on Raúl García, before Alba then joins him in the book for giving the referee too much lip.

Here's a shot of that disallowed Iñaki Williams own goal, by the way. The Athletic forward is clearly offside when the ball is flicked on.

Capa crosses to the back post, where Raúl García gets his head on it - but it's not powerful enough to trouble Ter Stegen. It's been a good couple of minutes for the hosts, and a good contest in general thus far.

Unai Núñez strides out of defence, plays a one-two with Raúl García and chests the ball down in the box, but can't quite bring it under his spell. With a trio of Barcelona defenders descending on him, he's quickly run out of it, much to his evident frustration. It would have been quite a goal had he managed to finish it off.

But from the goal-kick, Ter Stegen almost gifts Athletic the opener! The German plays the ball straight to Dani García, who pings it straight back towards the Barça goal... but sends his shot just past the corner of post and bar!

Athletic earn themselves another free-kick on the right. Muniain stands over it again. Can he swing over a better ball this time? He can, whipping it down the corridor of uncertainty and forcing Piqué to knock it behind. For some reason, however, Barça are given a goal-kick. San Mamés is not impressed.

Just as I say that, Messi very nearly locates Alba's dangerous run to the Athletic back post. His pass is just overhit.

In the main, Barcelona seem to be finding a better possession-to-end-product ratio. That said, it's been all Barça ball for about the last four minutes without the visitors managing to create anything of note.

It's been a frenetic first 20-odd minutes. Athletic's defenders are having to look exceedingly lively to keep Messi and Fati in check.

That's a fine challenge by Unai Núñez. Messi zips past Capa and into the Athletic box but, just as he cuts inside and prepares to pull the trigger, Núñez pulls off a perfectly-timed tackle to disposses the forward.

Athletic win a free-kick on the right flank, giving Iker Muniain the chance to swing one into the box. His delivery is easily repelled by Frenkie de Jong, however.

Fati tries to wriggle into shooting room in the box, and when his way to goal is blocked, the loose ball falls to Alba. He clips it to Messi on the penalty spot and the Argentine looks to ping a low strike towards Simón's far post, but again there's no way through. Yeray blocks.

Messi swings in a corner... which Williams heads clear with the minimum of fuss. It's been an eminently watchable opening period, it's fair to say.

Athletic have the ball in the net... but it's ruled out for offside. The corner from the left is flicked on to Iñaki Williams, who is all alone at the back post and prods home. He was clearly off, though.

Again Fati goes close! Semedo cuts the ball back from the Athletic byline and, with Messi's decoy run attracting several defenders, Fati spins and strikes from 12 yards - but defender Unai Núñez is there to block!

It's been an intense start at San Mamés; two decent chances already for Barça.

Barcelona's Nélson Semedo is the early recipient of the game's first yellow card, after scything down Iker Muniain.

Lionel Messi attracts three red and white shirts on the right-hand edge of the Athletic box, before slipping the ball across to Ansu Fati in shooting space. He controls, drops a shoulder and fires towards Unai Simón's near post... but it flashes just wide!

Athletic get Ander Capa barrelling forward into the Barcelona box, but the wing-back is deemed to have shoved over Jordi Alba and the chance is lost. And up the other end...

La Real hold on to oust Madrid

It's all over at the Bernabéu, incidentally, where Real Sociedad have knocked out Real Madrid - but were clinging on in the end. Having gone 4-1 up courtesy of Mikel Merino's 69th minute effort, La Real were then pegged back to 4-3 by goals by Rodrygo Goes and Nacho, but finally held on to take a major cup scalp and book their place in the semi-finals.

Peeeep! Underway at San Mamés.

Athletic victorious in last home Copa clash with Barça

Athletic also came away victorious the last time the teams met in the Copa in Bilbao, by the way, Aduriz and Iñaki Williams giving Los Leones a 2-1 first-leg triumph in a last-16 tie that was finally won by Barcelona, 4-3 on aggregate.

The Barcelona bench, meanwhile, is: Peña, Arthur, Griezmann, Umtiti, Junior Firpo, Vidal and Collado.

Aduriz worldie the difference last time the sides met in Bilbao

The last time Athletic and Barcelona met here, Aritz Aduriz’s stunning late overhead kick gave the hosts a 1-0 opening-day LaLiga victory in August. The 38-year-old, who is to retire at the end of the season, is among the substitutes.

The Athletic subs' bench in full is: Ezkieta, San José, Larrazabal, Lekue, Ibai, Aduriz and Villalibre.

Athletic in quarters after edging Tenerife

And though Athletic have come through four rounds of the Copa in that time, they needed penalties to beat second-tier opposition in the last two, most recently squeaking past Tenerife after a 3-3 last-16 draw at the Estadio Heliodoro Rodríguez Lopéz.

Hosts Athletic on decidedly iffy run of form

As for Athletic, they may be undergoing fewer off-the-field ructions right now, but their recent on-field fortunes haven't been the best, it must be said. Sunday’s 2-0 home defeat to Getafe made it seven games without a league win for Los Leones, who now sit ninth in LaLiga.

Messi looks "like he has one foot out of the door"

But with the good ship Barça navigating rather choppy waters right now, it's worth remembering that the terms of Messi's contract allow him to leave for free this summer - and it is being reported that no fewer than five potential suitors are busy preparing huge pots of gold with which to entice the Argentine.

One man who fears Messi may soon be on his bike is former Barça player Francisco José 'Lobo' Carrasco, who told the Spanish TV show 'El Chiringuito' on Tuesday: "He's ill at ease. In all the years I've been watching him and have loved the way he plays [...], it's the first time Messi has looked to me like he has one foot out of the door. I've never had to say that before."

(Photo: Marc Gonzalez Aloma/AFP/Europa Press)

"There are problems in every club"

Speaking ahead of tonight's match, Setién did his level best to appear unconcerned by the row, telling reporters he had spoken about it with his players for no more than "one minute", and adding: "There are problems in every club in the world. There are things I won't be able to control. Speak to me about football; the rest doesn't interest me."

(Photo: Alejandro García/EFE)

Abidal stays as sporting director - for the time being...

Messi's response is said to have the backing of all his fellow squad members, but despite speculation that this rift between players and sporting director could see Abidal given the heave-ho by Josep María Bartomeu, he remains in his post after emergency talks with the Barça president. For now, at least...

Abidal takes swipe at Barcelona players, Messi bites back

In an interview in Catalan newspaper Sport, Barça sporting director Éric Abidal suggests the squad basically downed tools under former coach Ernesto Valverde - some players "didn't work hard", he says - and his words are met by a swift, forthright reponse from club captain Lionel Messi.

"I think that when someone mentions players, they should give names," Messi wrote on Instagram on Tuesday, "because if they don't, they are tarring everyone with the same brush and fuelling gossip - a lot of which is not true."

(Photo: Lluis Gene/AFP)

Camp Nou crisis

So, where to start with what's been happening at Barcelona in the past few days? First, they lose Ousmane Dembélé for the rest of the season to yet another injury, leaving Setién with just 16 available first-team players. Then the blue-touch paper gets well and truly lit.

(Photo: Josep Lago/AFP)

Real Sociedad restore three-goal lead

Mikel Merino has now scored Real Sociedad's fourth at the Bernabéu... Follow it live here.

Granada and Mirandés already in semi-final hat

Aside from the winners of that Real Madrid-Real Sociedad tie, Athletic and Barcelona will be fighting it out to join Granada and giant-killers-in-chief Mirandés in Friday's draw for the semi-finals.

Having already made it all the way to the semis in 2012, second-tier Mirandés have repeated the feat this season, dumping top-flight Villarreal out of the quarter-finals with a 4-2 win on Wednesday.

Meanwhile, Roberto Soldado's stoppage-time penalty against his former club saw Granada claim a 2-1 victory over Valencia to end the holders' trophy defence on Tuesday.

(Photo: Edu Del Fresno/ZUMA Wire/dpa)

La Real leading Los Blancos at the Bernabéu...

Something of a Copa del Rey surprise could well be unfolding at the Bernabéu, where Real Madrid trail Real Sociedad 3-1. Marcelo pulled one back for the hosts a few moments ago, after a Martin Odegaard strike and a double by Alexander Isak had put the Txuri-Urdin three to the good.

There's half an hour to go in the Spanish capital, and you can follow live-text coverage of that clash right here.

Griezmann out, Roberto in for Barcelona

Quique Setién makes just the one change to his Barcelona side, as Antoine Griezmann makes way for Sergi Roberto. Ansu Fati starts once more after his two-goal haul in the win over Levante on Sunday.

(Photo: AFP)

Three changes for hosts Athletic

Athletic head coach Gaizka Garitano makes three changes to the team that lost to Getafe at the weekend, as Mikel Vesga replaces Unai López in midfield; striker Asier Villalibre drops to the bench, allowing defender Unai Núñez to complete what looks like being a back three; and Ander Capa takes up the right wing-back role in place of Íñigo Lekue.

Barcelona team news

Starting line-up: Ter Stegen, Semedo, Piqué, Lenglet, Alba, Rakitic, Busquets, De Jong, Roberto, Messi, Ansu Fati

Athletic Bilbao team news

Starting line-up: Simón, Capa, Yeray, Núñez, Martínez, Yuri, D. García, Vesga, R. García, Muniain, Williams

Athletic Bilbao vs Barcelona: ¡bienvenidos!

Evening! Welcome to our live coverage of the last of the 2019/20 Copa del Rey quarter-finals - a tie which pits the tournament's two most successful clubs against one another.

30-time Copa winners Barcelona visit 23-time victors Athletic Bilbao at San Mamés tonight, in a clash whose build-up has, at least from a Blaugrana point of view, been somewhat overshadowed by off-field goings-on.

More on that in a mo, but with our 21:00 CET kick-off now just under an hour away, the team news is in in Bilbao. So let's get to that first...