AZ Alkmaar continued on top of the Eredivisie after victory over RKC Waalwijk.
AZ were still at the summit after Twente failed to take advantage on Saturday, when they drew, and they made no mistake.
But they did make hard work of their clash at the AFAS Stadion as they could only claim a 1-0 win.
The winner arrived just after the break, with Icelandic forward Johann Berg Gudmundsson pouncing.
Ajax turned on the style to strike what could be a telling blow in this season's title race by beating PSV Eindhoven in Amsterdam.
The two sides went into the game four and five points behind leaders AZ Alkmaar respectively and, by the time the full-time whistle had been blown, the Amsterdammers had shaken clear of their opponents to open up a gap between the top two and the rest.
The two goals came inside seven second-half minutes, with Ismail Aissati opening the scoring (56) and Siem de Jong adding a penalty.
Feyenoord cruised to a 3-0 victory at bottom-of-the-table De Graaschap which took them back up to fifth.
The Rotterdam club did not make the breakthrough until 19 minutes from time when loan star John Guidetti scored.
Goals from Ruben Schaken and Sekou Cisse sealed the win for the visitors.
Heracles eased to a 3-1 win over Utrecht at the Polman Stadion.
The home side were ahead just minutes in when Swede Samuel Armenteros netted.
Utrecht were back on level terms just after the break when Cedric van der Gun scored - but the home side won it thanks to a brace from Ninos Gouriye.