AZ Alkmaar lost ground in the battle for European football as they were held to a draw at NEC Nijmegen.
The mid-table hosts took the lead after 13 minutes when Genero Zeefuik finished from close range, and AZ needed a Ruud Boymans header just before the hour mark to rescue a point.
The result means AZ have fallen two points behind Heerenveen - winners tonight - in the battle for fourth place and automatic Europe League qualification.
NEC, hoping to sneak into the Europa League play-offs themselves, began the game brightly and Remy Amieux was close to giving them an eighth-minute lead with a neat backheel from Zeefuik's cross.
It seemed to give the on-loan PSV Eindhoven man ideas, however, as it was with his backheel that Zeefuik turned in the opening goal after Navarone Foor's shot was blocked.
The hosts continued to push, with Esteban Alvarado called on to deny Krisztian Vadocz twice in quick succession.
It was not until first-half stoppage time that AZ had their first sight of goal, but Brett Holman volleyed over when picked out by Boymans.
Zeefuik fired narrowly over early in the second half as the hosts sought to double their lead in anticipation of an AZ fightback that was only moments away.
Boymans headed narrowly over from Rasmus Elm's corner in the 56th minute, but found the leveller moments later when he got on the end of Simon Poulsen's cross to score.
However, they never looked like finding a winner and it was NEC who had the best chance of the final half hour, with Melvin Platje volleying narrowly over when Foor's cross.