Davy Klaassen scored twice as Ajax Amsterdam trounced SC Cambuur 5-1 to extend their lead at the top of the Eredivisie.
Ajax maintained their three-point advantage over Feyenoord with a 1-1 away draw on Sunday, as PSV Eindhoven jumped into second spot.
Feyenoord lost ground in the Eredivisie title race after a shock 1-0 loss against ADO Den Haag.
Ajax and Feyenoord both recorded 3-1 victories on Sunday to remain locked together at the top of the Eredivisie.
Nigel Hasselbaink hit a 92nd-minute equaliser to earn Excelsior a 1-1 draw against PSV Eindhoven on Saturday night.
Gaston Pereiro was PSV Eindhoven hero as he scored twice in a 2-1 win against previously-unbeaten Eredivisie leaders Ajax.
Napoli made it three wins out of three for Italian sides in the Europa League on Thursday night with a 2-0 victory at Legia Warsaw.
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.
Ajax's Anwar El Ghazi scored twice in a 4-0 win over ADO Den Haag that took them clear at the top of the Dutch league on Sunday.
There were wins for Ajax and Feyenoord in the Eredivisie on Sunday, while FC Twente slipped to defeat.
Ajax started their Eredivisie campaign with victory over AZ Alkmaar, while Willem II and Vitesse played out a 1-1 draw.
Watford have completed the signing of Steven Berghuis from AZ Alkmaar.
Watford are set to make AZ Alkmaar forward Steven Berghuis their 10th signing of the summer.
Marco van Basten is returning to the Netherlands back-room staff as assistant to new coach Danny Blind.
Marco van Basten talks Sacchi, Michels and Cruyff, and why he walked away from management.
AZ claim a Europa League place at the expense of Feyenoord, who were consigned to the play-offs for a place in Europe.
Eredivisie champions PSV Eindhoven have made Danish defender Simon Poulsen their first signing of the summer.
NAC Breda face a relegation play-off, while Manchester United-bound Memphis Depay scored for PSV.
AZ Alkmaar remain in contention to clinch a Europa League berth from the Eredivisie after a 2-0 win at FC Twente.