Ajax and PSV lost ground in the Eredivisie title race as their 1-1 draw at the Amsterdam Arena left Feyenoord with a five-point advantage at the summit.
Leaders Feynoord are looking for their first league title since 1998-99 and secured a 3-1 victory over Vitesse Arnhem at De Kuip on Saturday.
Neither Ajax nor PSV were able to keep pace with Giovanni van Bronckhorst's side in their final matches before the mid-season break.
Ajax lost Anwar El Ghazi and Kasper Dolberg to injury in the first half but took the lead three minutes after the restart when Davy Klaassen cut across the ball to lash home a fine strike from 20 yards.
However, Siem de Jong denied his former club the three points, bringing down Gaston Pereiro's lovely ball over the top and guiding a finish beyond Andre Onana to earn PSV a share of the spoils.