Ajax lost ground in its bid to win the club's first Dutch league title in seven years after missing a late penalty in a 2-2 draw at Roda JC on Sunday.
The visitors were awarded a spot kick in the 88th minute, but striker Mounir El Hamdaoui missed his attempt.
Ajax led 1-0 when Miralem Sulejmani latched onto a pass from Christian Eriksen to score after 13 minutes, and teammate Siem de Jong doubled the lead in the 34th.
But Roda hit back with Mads Junker's goal seven minutes later and Anouar Hadouir, playing in his 200th league match, equalized with a free kick in the 82nd.
PSV Eindhoven and FC Twente both won Saturday to share the lead in the standings, five points ahead of third-place Ajax.
SC Heerenveen boosted its Europa League chances with a 2-0 win over NAC Breda. Luciano Narsingh scored in the 60th minute and created the other for Oussama Assaidi in the 82nd.
Niki Zimling's two second-half goals sealed NEC Nijmegen's 2-0 win over Excelsior Rotterdam, while FC Groningen drew 1-1 at De Graafschap.
On Saturday, it was: ADO The Hague 3, VVV-Venlo 0; Willem II 3, FC Utrecht 3; Twente 1, Vitesse Arnhem 0; Feyenoord 2, Heracles Almelo 1 and AZ Alkmaar 0, PSV 4.
