Ajax staged a late rally to beat PSV Eindhoven 3-1 on Sunday to give their faint title hopes a boost.
Feyenoord slipped 20 points behind leaders PSV in Eredivisie after a 2-0 defeat at lowly Heracles on Saturday.
Ajax lost 1-0 at Vitesse Arnhem on Sunday to fall further behind PSV in the Eredivisie title race.
PSV Eindhoven re-established their four-point lead at the top of the Eredivisie after edging to a 1-0 win at Vitesse.
PEC Zwolle moved up to fifth in the Eredivisie as they beat ADO Den Haag 3-1 and FC Twente drew 2-2 against Vitesse.
Ajax were held to a 1-1 draw at ADO Den Haag in the Eredivisie on Sunday, while FC Twente lost at home to FC Groningen.