Good evening and welcome to Eurosport's LIVE coverage of this Copa del Rey quarter final between Athletic Club and Barcelona. We'll bring you all the action as it happens at San Mames. Kick off is at 20:00 GMT.

On the same night, both Barcelona and Real Madrid are out of the Copa del Rey! What drama at the San Mames! This match looked destined for extra time, but Williams' stoppage time winner sends Athletic Club into the semi finals where they will be favourites along with Real Sociedad to go all the way! Wow!

FULL TIME: Athletic Club 1-0 Barcelona

Is there time for one last Barcelona chance to salvage this? They are lumping balls forward with everyone sent up from the back! This wasn't what they expected under Setien!

GOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOAL! Athletic Club (93 mins - Inaki Williams) Barcelona 0. It's a winner right at the death! It's Williams! Athletic Club have surely won this! He got his head to a cross into the box and glanced the ball into the far corner of Ter Stegen's net! Barcelona's players have slumped to the ground! They know that this is likely the winner!

There will be four minutes of stoppage time played at the end of the match.

Williams puts it wide! That was the chance for Athletic Club to claim the victory! The cross to the back post found Williams completely unmarked, but he scuffed his volley wide of the near post.

Raul Garcia gets a good ovation from the home supporters and on comes Gomez in his place.

That was the big moment! Messi was clean through, he was surely favourite to find the back of the net following the pass from Arthur, but Simon makes the save with his legs! What a save from the goalkeeper at this stage of the match!

Barcelona have to go to the Benito Villamarin on Sunday to take on Real Betis. That's a tough place to visit and injuries are now starting to take their toll on the Catalans with Pique a doubt now.

ANOTHER Barcelona player is shown a yellow card. This time it's Arthur who enters the referee's book.

Williams... smashed over! Aduriz flicks on a header for his strike partner to latch on to, but Williams lashes a wild shot into the crowd when he needed to show a little bit more composure in that position.

Indeed, there is the change from Barcelona and the injured Pique comes off to be replaced by Umtiti.

Pique's injured! Barcelona are going to be forced into a change here. Pique has hit the ground and Umtiti is getting ready to come on for the final 10 minutes. That's a blow to the Catalans.

Aduriz comes on for the final 10 minutes. The veteran striker replaces Muniain.

Messi is now dropping deep to pick up the ball and drive it forward. Griezmann is buzzing around ahead of the Argentine trying to open up pockets of space in behind.

15 minutes left to play and this one could still swing either way. A place in the semi finals of the Copa del Rey is the prize for the victor with Atletico Madrid and Real Madrid already out.