Heracles moved to within a point of Eredivisie leaders Ajax after a 2-0 win at home to Heerenveen.
There were Eredivisie wins for both Ajax and PSV on Saturday, while second-placed Heracles slipped to defeat.
Wout Weghorst scored the only goal as high-flying Heracles beat ADO Den Haag 1-0 to climb to second in the Eredivisie.
Swansea have signed five-cap Sweden goalkeeper Kristoffer Nordfeldt to compete with Lukasz Fabianski for the No 1 spot.
Vitesse beat Heerenveen 5-2 as they claimed a Europa League place with a 7-4 aggregate win in the post-season play-offs.
AZ claim a Europa League place at the expense of Feyenoord, who were consigned to the play-offs for a place in Europe.