Ajax claimed the Eredivisie top spot in style on Sunday afternoon after crushing Heracles Almelo 6-0 at the Amsterdam ArenA.
Locked in a six-team battle for the crown, the Dutch giants took over at the summit with the decisive win.
Frank de Boer's men are firmly in the mix for the title, with their performance here sending out a clear warning sign to the rest.
They opened the scoring in the first half through Theo Janssen and then cut loose in the second, with Lorenzo Ebecilio, Christian Eriksen, Vurnon Anita, Siem de Jong and Kolbeinn Sigthorsson all finding the net.
AZ Alkmaar conceded the lead as they were held to a 2-2 draw by UEFA Europa League hopefuls Vitesse Arnhem at the Gelredome.
The visitors took the lead through American forward Jozy Altidore (32) but Vitesse hit back through Guram Kashia and Marco van Ginkel to forge ahead at the start of the second half.
Simon Poulsen was credited with AZ's equaliser just before the hour mark but the dropped points allowed Ajax to rise to the summit.
De Graafschap remain rooted to the foot of the Eredivisie table after a 2-0 defeat at NEC Nijmegen.
Going into the match two points behind Excelsior, Richard Roelofsen's men knew a three-point haul would lift them off the bottom of the pile.
But goals either side of the break from Lasse Schone and Genero Zeefuik ensured that mid-table NEC coasted to a comfortable success, aided by Lion Kaak's dismissal just prior to half-time.
Krisztian Nemeth's 23rd-minute strike was enough to hand RKC Waalwijk a 1-0 victory at home to ADO Den Haag.
RKC, the surprise package of the Eredivisie this season, now sit ninth in the table, while ADO are struggling down in 15th.