Match ends, Real Madrid 1, Espanyol 0.
Real Madrid moved top of La Liga after Marco Asensio's VAR-awarded strike proved enough to beat Espanyol.
Asensio drilled in a low shot just before the break when Luka Modric's effort deflected into his path, with the goal given after a lengthy review.
Borja Iglesias hit the crossbar for the spirited visitors with a deft chip.
Former Real keeper Diego Lopez made a fine save to deny Sergio Ramos late on in an otherwise stilted performance by the hosts at the Bernabeu.
Victory takes Julen Lopetegui's side above rivals Barcelona, who can retake the top spot with a draw or victory against Girona on Sunday.
Espanyol drop to sixth following Atletico Madrid's 2-0 win over Getafe earlier on Saturday.
Isco and Asensio highlight new era
Real made sure of victory with a functional rather than fluent performance, maintaining their unbeaten league start under new boss Lopetegui.
Isco and Asensio once again showed how vital they will be to the new era at the Bernabeu after the departure of talisman Cristiano Ronaldo and three-time Champions League-winning manager Zinedine Zidane over the summer, the Spain pair central to most of their side's best moves.
Asensio was unmarked when Modric's blocked strike fell to him and clinically found the far bottom corner as Espanyol appealed for offside.
Referee Antonio Miguel Mateu Lahoz consulted VAR and after a long delay awarded the goal, with replays showing Asesnio was clearly onside, as the midfielder appeared to joke about the wait with his celebration, pointing to his wrist.
Isco then created Real's best chance in the latter stages, curving an immaculate cross with the outside of his right foot, only for Lopez to tip the onrushing Ramos' header over the bar.
The lack of fluency could also be down to the hosts making five changes from the side that beat Roma in the Champions League on Wednesday, with Gareth Bale an unused substitute.
Espanyol fail to exploit shaky Real defence
While right-back Alvaro Odriozola made a largely assured debut, Real's defence as a whole was suspect at times but Espanyol failed to take advantage.
Pablo Piatti shot just wide after Real were slow to react to a sweeping Espanyol counter, before former Chelsea keeper Thibaut Courtois saved from Hernan Perez.
After the interval, Ramos was caught dallying in possession on the edge of his own area, with Iglesias robbing him off the ball and beating Courtois with an exquisite lob only to see it ricochet back off the bar.
Despite that warning, Ramos continued to streak forward at will, with Casemiro forced to race back and cover on several occasions. The experienced Spaniard could have cost his side the win, had the visitors been more clinical with their final ball.
- 6NachoBooked at 6mins
- 14CasemiroBooked at 77mins
- 24CeballosSubstituted forVázquezat 63'minutes
- 22IscoSubstituted forLlorenteat 79'minutes
- 9BenzemaSubstituted forMarianoat 60'minutes
- 16López RodríguezBooked at 45mins
- 5Gomes Pereira
- 21RocaBooked at 26mins
- 17PérezSubstituted forGarcíaat 70'minutes
- 10DarderSubstituted forSánchezat 55'minutes
- 19PiattiSubstituted forBaptistaoat 55'minutes
- Antonio Miguel Mateu Lahoz
- Shots on Target
Second Half ends, Real Madrid 1, Espanyol 0.
Luka Modric (Real Madrid) wins a free kick in the attacking half.
Foul by Víctor Sánchez (Espanyol).
Foul by Marcos Llorente (Real Madrid).
Javi López (Espanyol) wins a free kick in the defensive half.
Hand ball by Esteban Granero (Espanyol).
Casemiro (Real Madrid) wins a free kick in the defensive half.
Foul by Dídac Vilá (Espanyol).
Attempt saved. Marcos Llorente (Real Madrid) right footed shot from the right side of the box is saved in the centre of the goal. Assisted by Mariano.
Corner, Espanyol. Conceded by Sergio Ramos.
Attempt blocked. Leo Baptistao (Espanyol) right footed shot from the left side of the box is blocked. Assisted by Borja Iglesias.
Attempt missed. Marco Asensio (Real Madrid) left footed shot from outside the box is high and wide to the left. Assisted by Mariano.
Luka Modric (Real Madrid) wins a free kick in the defensive half.
Foul by Leo Baptistao (Espanyol).
Attempt missed. Javi López (Espanyol) right footed shot from the centre of the box misses to the left. Assisted by Esteban Granero following a corner.
Substitution, Real Madrid. Marcos Llorente replaces Isco.
Corner, Espanyol. Conceded by Raphael Varane.
Attempt blocked. Esteban Granero (Espanyol) right footed shot from outside the box is blocked.
Casemiro (Real Madrid) is shown the yellow card for a bad foul.