Dusan Tadic converted a 59th minute penalty to hand Steve McClaren's side another three points against winless Heerenveen.
PSV Eindhoven scored three second-half goals to brush aside Feyenoord 3-0.
The home side, without the suspended Mark van Bommel, took control just past the hour when Ola Toivonen scored with a curling shot from 20 metres.
Former Feyenoord player Georginio Wijnaldum doubled the lead with a close range header before Luciano Narsingh netted a rebound.
Ryan Babel scored his first goal since rejoining Ajax Amsterdam, his second-half equaliser earning a 1-1 draw at ADO Den Haag who had led through Tom Beugelsdijk