There were Eredivisie wins for both Ajax and PSV on Saturday, while second-placed Heracles slipped to defeat.
Ajax returned to the top of the Eredivisie with a 2-0 victory over Excelsior on Sunday.
There were wins for Napoli, Borussia Dortmund and Marseille on matchday one of the Europa League.
Wout Weghorst scored the only goal as high-flying Heracles beat ADO Den Haag 1-0 to climb to second in the Eredivisie.
Mimoun Mahi scored a couple of late goals as Groningen beat Excelsior 2-0 to claim their first win of the Eredivisie season.
Michael de Leeuw rescued a point for Groningen in a 1-1 draw with Twente in the Eredivisie on Wednesday, as NEC beat Excelsior 1-0.