But at ADO Den Haag the game was called after 80 minutes with PSV Eindhoven 2-0 ahead when referee Rene Temmink took exception to insults aimed at him from the home crowd.
PSV had taken the lead through Johan Vonlanthen after 41 seconds and the young Swiss international doubled the advantage eight minutes into the second half.
PSV remain top with 19 points, three above Feyenoord and Utrecht, who travel respectively to Roda JC Kerkrade and Groningen on Sunday.
Ajax are fourth with 15 points and struggling ahead of Tuesday's Champions League match at home to Maccabi Tel Aviv.
Ronald Koeman's squad, without the injured Rafael van der Vaart and Tomas Galasek, took the lead 12 minutes before halftime when Yannis Anastasiou met a corner kick.
Heerenveen, who travel to Benfica on Thursday for a UEFA Cup group game, equalised eight minutes into the second half when Ugur Yildirim found his way through the Amsterdam defence and beat goalkeeper Bogdan Lobont with a fierce shot.
Eight minutes later Mika Vayrynen shocked the home side with Heerenveen's second goal and Stefan Selakovic secured victory with a minute remaining to steer his team to sixth spot.
