In a rare early kick-off at the Nou Camp, Alexis Sanchez opened the scoring with his first goal of the season after less than six minutes and Lionel Messi celebrated putting pen to paper on his two-year contract extension earlier this week by notching - for the 13th straight game in La Liga - on 13 minutes.
David Villa's neat finish made it 3-0 in the 57th minute and substitute Cristian Tello added another 11 minutes from time.
Getafe substitute Alvaro Vazquez then grabbed a consolation for the visitor but there was still time for Andres Iniesta and Gerard Pique to add further gloss to the scoreline for the host.
First half strikes from Alhassane Bangouraan and Leo Baptistao saw Rayo Vallecano to victory in the Madrid derby over Atletico.
Second-placed Atletico - which had lost just one of its last 10 - was never in the game with Radamel Falcao's last-gasp strike a mere consolation, while defensively its inability to stop and defend crosses into the box was its downfall.
In contrast, Rayo defended bravely and showed why it are so imperious at home, with an impressive attacking display to register its fifth victory in its last six matches at the Estadio Teresa Rivero.
Real Sociedad boosted its push for a UEFA Europa League place as goals from Antoine Griezmann and Imanol Agirretxe saw off Real Zaragoza 2-1.
Zaragoza left-back Hector endured a nightmare league debut, sent off for two bookable offences after only 22 minutes to deal his team, already a goal down, a blow from which it would not recover.
Griezmann had opened the scoring after 11 minutes and Agirretxe doubled it shortly after the hour mark, with Zaragoza made to wait until deep in injury-time for Apono to get its goal from the penalty spot.
Espanyol climbed above Athletic Bilbao as it capitalised on a miserable day for the Basque side with a surprise 4-0 away win.
Athletic had plenty of chances and possession but no luck and Espanyol took full advantage with goals from Hector Moreno, Victor Sanchez, Christian Stuani and Joan Verdu, the latter following up on his own missed penalty.
Victor Alvarez set up the second and third goals within seconds of each other, and only moments after coming on as a substitute, and then won the penalty from which Verdu scored.