Ajax remained nine points behind Eredivisie leaders PSV Eindhoven after losing at mid-table Vitesse.
PSV extended their lead on Saturday as goals from Jurgen Locadia and Memphis Depay in the final six minutes give them a 2-1 win over Willem II.
Ajax failed to cut the gap as Vitesse's Uros Djurdjevic scored a fantastic goal, chesting the ball, flicking it past a defender and smashing home.
Frank de Boer has won the title in each of his four years as Ajax boss.
The Amsterdam side, who faced 25 shots - a record under De Boer in the league, have now lost three Eredivisie games this season, as many as they did in 2013-14.
Vitesse are up to 10th with the surprise victory.
- 40DiksBooked at 75mins
- 23van der Heijden
- 8QazaishviliSubstituted forLeerdamat 83'minutes
- 30IbarraSubstituted forOliinykat 23'minutes
- 27TraoréSubstituted forDjurdjevicat 83'minutes
- 2van Rhijn
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- 10KlaassenBooked at 57mins
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- Pieter Vink
- Shots on Target