Two goals in the space of five second-half minutes ensured Ajax claimed a 2-1 win over previously undefeated Eredivisie leaders PEC Zwolle on Saturday.
The Blauwvingers have been the league's surprise packages after beginning their campaign with four wins and a draw in their opening five matches but their clash with the defending champions was their sternest test to date.
The score remained goalless up until the 72nd minute when Thulani Serero put Ajax ahead before Maikel Van der Werff scored an own goal a little after and while Giovanni Gravenbeek pulled a goal back a minute from time at the Amsterdam ArenA, it was too little too late.
PEC still top the standings by a point after PSV Eindhoven were held to a 2-2 draw at FC Twente.
The hosts twice led through strikes from Shadrach Eghan (17) and Quincy Promes (70), but were pulled back on both occasions through Georgino Wijnaldum (66) and Memphis Depay (83).
Cambuur Leeuwarden claimed their second win of the season after easing to a 2-0 triumph at home to Heracles.
Michiel Hemmen's strike just before half-time put the hosts ahead in the 42nd minute and Bart Schenkeveld's own goal two minutes from time ensured there was no way back for Heracles.
ADO Den Haag's clash with Vitesse at the Kyocera Stadion was postponed due to a waterlogged pitch.