PSV Eindhoven's troubles show no sign of abating as a Luis Suarez brace earned Ajax a 4-1 win at the Amsterdam ArenA and sent them top of the Eredivisie table.
The Uruguayan scored once in each half to help earn a sixth straight league win for Marco van Basten's men, who moved ahead of NAC Breda on goal difference.
The champions, on the other hand, are looking a shadow of the title-winning side of last season as they slumped to their fourth defeat in a row in all competitions.
Suarez's opener was cancelled out by Ibrahim Afelley, but three goals in the final 16 minutes from Miralem Sulejmani, Suarez again and Leonardo sealed the win for Ajax.
NAC had maintained their title bid with 3-0 win over Heracles Almelo on Friday.
FC Groningen are up to third, two points off the leading duo, after making it six wins out of six at home with a 3-0 victory over struggling De Graafschap.
Danny Holla opened the scoring in the first half and goals in the final 13 minutes from Andreas Granqvist and Marcus Berg wrapped up victory.
AZ Alkmaar slipped to fourth, level on points with Groningen, after being held to a 1-1 draw at Vitesse Arnhem.
Santi Kolk snatched a point for the hosts after Ari had opened the scoring to lift Vitesse up to fourth from bottom.
A Roy Makaay penalty eight minutes into the second half earned Feyenoord a 1-1 draw at FC Twente.
Steve McClaren's side had gone in front through a spot-kick of their own, converted in the 13th minute by Blaise Nkufo.
In yesterday's action, FC Volendam fell to a heavy 4-0 defeat at the hands of Sparta Rotterdam.
The home side had to wait until the 73rd minute for Rydell Poepon to break the deadlock, but the floodgates then opened as Charles Dissels, Ruud Knol with a penalty and Joey Godee all found the target.
Volendam have just one win to their name this season and sit six points from guaranteed safety and Vitesse.
Roda JC boosted their survival hopes with a 3-0 win over NEC Nijmegen.
Sekou Cisse got the ball rolling after five minutes before two goals from Willem Janssen either side of half-time earned Roda only their second victory of the campaign.
Roda now lie third from bottom, two points ahead of De Graafschap and one behind Vitesse.
Ten-man Heerenveen went fifth on the back of a battling 3-2 win over FC Utrecht.
Ali Boussaboun's sixth-minute opener for Utrecht was immediately cancelled out by Danijel Pranjic before Roy Beerens put Heerenveen ahead after 41 minutes.
Tim Cornelisse fired Utrecht level on the stroke of half-time but Pranjic struck the winner seconds later.
Goran Popov was given his marching orders for Heerenveen five minutes after the restart, but Trond Sollied's men clung on for the three points.
In yesterday's other match, Frank Demouge's goal gave Willem II a 1-0 win over ADO Den Haag.