Celta Vigo's Fabian Orellana (R) fights for the ball with Barcelona's Neymar da Silva during their Spanish first division soccer match at Balaidos stadium in Vigo, Spain September 23, 2015. [Photo/Agencies]

VIGO, Spain - Celta Vigo swept to a shock 4-1 victory over Barcelona, while Real Madrid went top of the Spanish league with a 2-1 win over Athletic Bilbao Wednesday on a mixed night for the title contenders.

Two goals by Iago Aspas helped Celta to a convincing victory over Barcelona and second place in the table, level on 13 points with Madrid after five rounds. Celta is second for having conceded more goals than the capital club.

"There is always a day when your opponent is superior and can win all the balls and beat you in every individual duel and doesn't give you a chance - as has happened today," Barcelona defender Javier Mascherano said.

"There are no excuses, they beat us deservedly."

Karim Benzema scored twice for Madrid, opening the scoring in the 19th minute after intercepting a terrible back-pass by Mikel San Jose and racing forward to steer the ball past goalkeeper Gorka Iraizoz.

Sabin Merino equalized with a header, the first goal Madrid goalkeeper Keylor Navas has conceded this season, but Benzema scored his fifth goal so far this season after latching onto Francisco "Isco" Alarcon's pass in the 70th.

Elsewhere, Rayo Vallecano beat Sporting Gijon 2-1 and Levante drew 2-2 with Eibar. Villarreal beat Malaga 1-0, while Sevilla - that has yet to win a match this season and is bottom of the league - lost 2-0 to newly promoted Las Palmas in the Canary Islands.

Manuel "Nolito" Agudo opened the scoring in the 25th minute at Celta's Balaidos Stadium with a lofted shot that Barcelona goalkeeper Marc-Andre ter Stegen got his fingertips to, but couldn't keep out. It was the attacking midfielder's fifth goal this season.

Barcelona conceded again three minutes later when Aspas pounced on a poor pass by Gerard Pique, raced forward and lifted the ball over Ter Stegen.

Aspas then sprinted up the field and side-footed the ball past a stranded Ter Stegen in the 55th.

Neymar pulled one back for Barcelona by powering in Lionel Messi's pass in the 80th, but Sweden forward John Guidetti made it 4-1 from close range three minutes later.

Messi had forced a fine save in the first half and hit the post in the second on a luckless night for the Argentina forward.

"I prefer to be beaten by a team like Celta that plays a very clean game," said Barcelona coach Luis Enrique, whose side is one point behind the league leaders.