Afonso Alves' hat-trick sunk NAC Breda while Sparta Rotterdam beat bottom club ADO De Haag.
Alves opened the scoring for Heerenveen on nine minutes but Glen Salmon levelled matters shortly after.
Alves' second restored their lead before the break with Lasse Nilsson's goal extending their advantage on 64 minutes.
Heerenveen wrapped up the points when Alves completed his hat-trick, but there was still time for Salmon to net his second of the game late on.
There were also goals aplenty from Sparta's trip to Eredivisie strugglers ADO Den Haag.
The visitors were in cruise control thanks to a brace from Sjaak Polak and Cecilio Lopes.
Aleksander Rankovic pulled one back before Michael Krohn-Dehli restored Sparta's three-goal lead.
Former Leicester City striker Mark de Vries did give the home side the last laugh with an 80th minute consolation.
Excelsior have jumped two places into 15th in the Eredivisie table after a crucial 1-0 success at NEC Nijmegen.
Andwele Slory's goal six minutes before half-time proved the match-winning contribution.