La Liga leaders Barcelona continued their excellent early season form under Hansi Flick as they swept aside city rivals Espanyol to move nine points clear of Real Madrid.
Fresh from thrashing Real in their El Clasico encounter last week, Barca's attacking play was again sensational at times, with teenage winger Lamine Yamal once more looking a class above his contemporaries.
He bent in a wonderful cross with the outside of his foot which Dani Olmo turned in off the crossbar for the 12th-minute opener.
Another talented youngster, Marc Casado, then played an equally good ball in behind the Espanyol defence 11 minutes later, with captain Raphinha timing his run perfectly to clip the ball home.
Defensively, Barca's incredibly high line once again made life interesting, with Espanyol having two goals ruled out for narrow offside calls.
Full-back Omar el Hilali squared for Jofre Carreras to sweep in, but the strike was ruled out by the video assistant referee (VAR). Moments later, Olmo got his second with a thumping shot from the edge of the area to put Barca 3-0 up.
Early in the second half Alvaro Tejero's effort for the visitors was also ruled out after another close offside call.
Captain Javi Puado, though, swept in at the far post 18 minutes after the break to reduce the deficit.
Espanyol improved as Barcelona shut down, but the fourth-bottom side were second best throughout as their dismal derby record continued.
They have now gone 27 straight derbies without a win over Barcelona and have lost six of their past seven games in La Liga.
Flick's side have won 11 of their 12 league games under the German and, since their sole loss at Osasuna at the end of September, have won six in a row in all competitions, scoring 24 goals in the process.
They visit Red Star Belgrade in the Champions League on Wednesday and will look to maintain this wonderful run of form.
Earlier on Sunday, third-placed Atletico Madrid beat Las Palmas 2-0 to move to within a point of Real in the table.