Barcelona were stunned by Athletic Bilbao in the first leg of the Spanish Super Cup on Friday as Luis Enrique's men suffered a humiliating loss with the score reading an incredible 4-0 at San Mames.

This is not what the Barca boss had in mind as he made some key changes in the team opting to bench Andres Iniesta, Ivan Rakitic, Gerard Pique and Sergio Busquets, which turned out to be a disaster. Despite these players being benched, Barcelona had quality players in their starting eleven, including Lionel Messi and Luis Suarez amongst others to carve out a win, but it was not to be.

When one would have thought Lionell Messi would steal the show in the first leg, Striker Aritz Aduriz was the hero of the night with a hat-trick.

Barcelona conceded a goal in the 13th minute of the game, which was beautifully struck by San Jose to give them the lead and the hosts began to apply pressure when they had the ball. Despite a fair share of possession, Barcelona were not resembling a champion side as Athletic Bilbao came close a number of times.

The Spanish champions were lucky to head over to the tunnel 1-0, for things could have turned out much worse.

Hence, things were expected to get better for Barcelona in the second half as they even came close to drawing level as a Pedro shot hit the cross bar in the 50th minute.

Just when things were looking better for Barcelona, who were looking dangerous, Bilbao's Aritz Aduriz strike in the 53rd and the 62nd minutes killed all hopes of a Barcelona comeback. The night was made even worse with a penalty on the 68th minute, which was converted by Aritz Aduriz to complete his hat trick.

The match finished off 4-0, but Barcelona have one more chance to rectify their mistake during their second leg at home, where they need to score a bucket load of goals.

Manager Enrique believes they can still turn the results around on Monday night during the second leg.

"If anyone can turn this result around then it is Barca and if not we will still try with all we've got," Espn quoted manager as saying. "It is not being arrogant to think that we can come out on top.

"This was not our best performance but still we were not fortunate."

Watch match highlights below: