Athletic Bilbao beat European treble-winning side FC Barcelona in a 4-0 shocking win at the San Mames, the home stadium of the Copa Del Rey runners-up.

A hat trick from who clearly was the man of the match that night, came from Aritz Aduriz and an early goal from Mikel San José made the dream of not only reversing the scoreline next week at the Camp Nou just as hard, but it will definitely be a huge mountain to climb for the Blaugrana if they want to keep their sextuple dream alive.

Shambles in the back for the Catalans

It was a poor night for the Barcelona defense and their goalkeeper Marc-Andre ter Stegen, as the club conceded four goals for the first time since the 2012-13 UEFA Champions League semifinal against eventual champions Bayern Munich. However, on this night, this was something that really wasn't suppose to happen.

It started as early as the 13th minute, when Bilbao took the lead early from San José. As the German goalkeeper was trying to take away a clearance of the Lions of a header, the ball was falled into the midfielder and from almost the halfway line, he shoots the down from roughly that area for a wonder goal as ter Stegen was unable to do anything to get the ball in time.

Nevertheless, Barcelona tried to come back but just couldn't do it in the end. Luis Suarez came close to equalizing in the 26th minute, but Gorka Iraizoz after running out of goal was rescued by the defense who should get big praise for being able to stop the magician known as Lionel Messi from a few days after his brilliant performance against Sevilla in the UEFA Super Cup.

A night to remember

Despite not having player such as Iker Muniain, Mikel Rico and Inaki Williams, it was still the night for one Aritz Aduriz. Shortly after Pedro's chance hit the bar, A Sergi Roberto mistake gave Sabin Merino the chance to win ball from the Barca midfielder, as he went going on a brilliant run down the left, went for a cross from the byline, before Aduriz rises well with a great header to make double the lead. 

Surely, the sweet taste of revenge continued to become more sweeter and sweeter as again Aduriz scored a brace, just nine minutes later. Poor defending from Barcelona made them unable to clear the ball and after a cross in from the right-hand side, the experienced striker was able to thump home an emphatic finish as a result. Suddenly, Barcelona were down 3-0 to the Copa Del Rey runners-up.

The horror all ended in the 68th minute when Bilbao were awarded a penalty. Dani Alves dove into his man at the near post for no apparent reason and just like that, the 34-year-old striker sends Ter Stegen the wrong way with his spot kick to make it a ''poker'' for Bilbao and a mountain to climb for Barcelona.

A night to remember in Basque Country as the home side are 90 minutes away from winning their first ever title in any competition since 1984 while Barcelona, who might have regretted to not score an away goal tonight, will have to score five and not concede any to keep their sextuple dream alive at home next week.