PSV Eindhoven went to the top of the Eredivisie with a 4-0 home victory over Heracles, while Ajax's unbeaten league run ended.
With FC Twente not in action until Sunday afternoon (local time), when it tackles Feyenoord, PSV seized its chance to move two points clear.
Ajax was the last undefeated team in the Dutch top flight, but that bare fact masked that its record showed only four wins from 10 games, the others all being drawn.
The Amsterdam giant remains sixth in the table, now nine points behind PSV, after a 2-0 loss at home against third-placed Vitesse, for whom Wilfried Bony scored in the 38th and 46th minutes.
Ajax heads to
FC Utrecht stands fourth in the table after a 5-1 win away to second-bottom Willem II.