Heracles moved above Heerenveen in the Eredivisie after a convincing 4-2 victory at the Polman Stadion.
The hosts scored four times in the opening hour - through Everton, Samuel Armenteros, Antoine Van der Linden and Darl Douglas - with Mika Vayrynen and Philip Haglund grabbing Heerenveen's replies.
FC Groningen strengthened their bid for European football next season with a 1-0 victory over NAC Breda.
Andreas Granqvist's 72nd-minute strike proved to be the only goal of the game but Groningen also missed a penalty. Granqvist got the ball inside the area but moved away from goal to make space before unleashing a thunderbolt of a shot.
Groningen had two great chances to add to their lead, but Tim Sparv headed against a post in the 79th minute and moments later Dusan Tadic saw his penalty saved after Jonas Ivens was brought down inside the area by Rob Penders.