PSV Eindhoven leapfrogged their title rivals to go two points clear at the summit with a 3-1 win over Vitesse Arnhem on Friday night, and remained there after AZ's lacklustre performance at the Parkstad Limburg Stadion.
Sanharib Malki put Roda in front in the 10th minute, with Mads Junker adding the second goal 12 minutes before half-time.
Elsewhere on Saturday night, Bas Dost bagged his 17th goal of the season in Heerenveen's 2-0 home win over FC Utrecht.
Dost netted with a header after 12 minutes and Jeffrey Gouweleeuw scored the second two minutes later as Heerenveen keep up their bid for a place in Europe.
Heracles Almelo piled the misery on Excelsior with a 3-0 triumph over the bottom team at the Polman Stadion.
Ben Rienstra opened the scoring in the 18th minute and Kwame Quansah doubled the hosts' advantage nine minutes later.
Glynor Plet then ended any hopes of an unlikely comeback by the visitors with a third goal four minutes after the interval, although Heracles had to play for most of the second half with 10 men after the 53rd-minute dismissal of Lerin Duarte.
Finally, struggling De Graafschap were left to rue their luck after their 1-1 draw at NAC Breda.
The visitors took a surprise lead through Michael de Leeuw after eight minutes, but found themselves pegged back four minutes later courtesy of Anthony Lurling's strike.
Thereafter it was De Graafschap who had the better chances but they hit the woodwork twice and found NAC keeper Jelle ten Rouwelaar in good form.
