Isco scored twice as Real Madrid reduced the gap on La Liga leaders Barcelona to seven points courtesy of a 2-0 win over Espanyol on a day where football was dragged into violent political clashes in Catalonia.

Barca had earlier extended their perfect start in La Liga to seven games in extraordinary circumstances as they beat Las Palmas 3-0 behind closed doors at the 99,000 capacity Camp Nou following the police crackdown over an independence vote deemed illegal by the Spanish government.

At least 500 people were injured as Spanish riot police fired rubber bullets and forced their way into activist-held polling stations.

Following La Liga's refusal to abandon the match, Barca decided to play behind closed doors as a means of protest.

Outspoken Barca defender Gerard Pique broke down in tears as he described the day as "the worst professional experience I have had in my life."

The political tension also bubbled over at the Santiago Bernabeu where Real fans waved Spanish flags and sang 'Viva Espana' (long live Spain).

On the field there was far less conflict as Real eased to an 11th consecutive win over Barcelona-based Espanyol for their first home league win of the season.

"We have to be happy. The important thing was the three points after three games without winning here," said Madrid coach Zinedine Zidane.

Isco was denied the opening goal inside 30 seconds by Espanyol goalkeeper Pau Lopez.

But the Spanish international made no mistake when he prodded home Cristiano Ronaldo's pass for the opener on 30 minutes.

Ronaldo volleyed over and then fired straight at Lopez when clean through.

However, Espanyol had a slew of chances themselves to level.

Gerard Moreno hit the post just before the break, whilst Keylor Navas denied Marc Navarro and Nacho produced a brilliant goal line clearance to prevent Leo Baptistao a tap in.

Espanyol's profligacy was finally punished 19 minutes from time when Isco curled home his second of the evening at the end of a rapid counter-attack.

"He is a player that plays like he's on the street," Zidane added on Isco's impressive form.

"I like that. He doesn't worry when things don't go his way."

Victory lifts Madrid up to fifth behind Barca, Sevilla, Valencia and Atletico Madrid.

Valencia's great start under Marcelino Garcia Toral's tutelage continued with a thrilling 3-2 win over Athletic Bilbao.

Simeone Zaza and Dani Parejo's penalty gave the hosts a 2-0 half-time lead.

Aritz Aduriz reduced the arrears for Athletic, who have now gone six games without a win.

Rodrigo restored Valencia's two-goal cushion before Raul Garcia's late consolation.

The game of the day was undoubtedly at Anoeta where Real Sociedad and Real Betis drew 4-4.

Three times Betis led thanks to goals from Antonio Sanabria, Zoudhair Feddal, Joaquin and Sergio Leon.

But Sociedad kept roaring back as Diego Llorente's header four minutes from time salvaged a point after earlier strikes from Willian Jose, Mikel Oyarzabal and Xabi Prieto.

Villarreal get off to a winning start under new coach Javi Calleja as Cedric Bakambu hit a hat-trick to see off Eibar 3-0.