Feyenoord's Kenneth Vermeer made a costly error as Heerenveen maintained their remarkable Eredivise run, while PEC Zwolle rose up to third.
Kenneth Vermeer's error proved costly as Feyenoord's four-match Eredivisie unbeaten streak came to an end as Heerenveen extended their remarkable run of form with a 3-1 victory.
After Simon Thern's effort had cancelled out Colin Kazim-Richards' first-half opener, former Ajax goalkeeper Vermeer spilled Sam Larsson's long-range but tame effort into his own net to give the hosts the advantage just before the hour-mark.
Larsson then doubled his tally with 13 minutes remaining to put the result beyond all doubt and continue Heerenveen's fine league run, which sees them unbeaten since November.
Stefan Nijland bagged a brace as PEC Zwolle took advantage of Feyenoord's loss to leapfrog them into third with a 4-0 demolition of lowly Dordrecht.
It was not all plain sailing for the hosts against their 18th-placed opponents however, as, after Nijland opened the scoring just prior to half-time, they had to wait until the 79th minute to extend their lead through Sheraldo Becker.
Jesper Drost then added another before Nijland notched Zwolle's fourth - his 10th of the campaign - a moment later.
Meanwhile, in-form FC Twente - who had won their past three fixtures in all competitions - were beaten 2-0 away at ADO Den Haag.
The result sees Den Haag jump up to 14th, while Twente remain in sixth, four points behind the top four.
Valeri Kazaishvili's first goal since September helped Vitesse to a convincing 2-0 win at Cambuur, who have now lost their past three league fixtures.
Willem II bounced back from their loss to PSV with a hard-fought 1-0 win over FC Utrecht thanks to Robbie Haemhouts' 80th-minute goal.