PSV restored their four-point lead at the top of the Eredivisie with a 1-0 win at Vitesse Arnhem on Saturday.
Reigning champions Ajax had closed the gap to a single point with victory against Groningen on Friday, but Phillip Cocu's men responded as Adam Maher scored the only goal of the game after 10 minutes.
It was the midfielder's seventh league goal of the season and extended the Eindhoven club's unbeaten league run to 11 matches.
PEC Zwolle climbed to third, 10 points behind Ajax, after thrashing NAC Breda 4-1 at home thanks to three goals in eight second-half minutes.
Bart van Hintum put the hosts in front early on before Moroccan Adnane Tighadouini equalised 12 minutes into the second half.
Parity lasted just six minutes however, as goals from Jesper Drost, Jody Lukoki and Ben Rienstra followed in a devastating spell, which would secure a fifth win in six matches for the European hopefuls.
The result lifted Ron Jans' side above Feyenoord, albeit having played a game more with the Rotterdam club in action against FC Twente on Sunday.
AZ remain just a point behind Zwolle, in fifth position, after goals either side of half-time from Simon Poulsen and Nemanja Gudelj extended bottom club Dordrecht's winless league run to 17 games.
Cambuur twice pegged back Ado Den Haag with Bartholomew Ogbeche the scorer on both occasions, as the points were shared.
Mike van Duinen had given Den Haag a first-minute lead and Roland Alberg restored the advantage after the first equaliser, but neither team could find a winner.
