Second-placed Ajax needed a victory over rivals Feyenoord to keep the pressure on Eredivisie leaders PSV Eindhoven when the two sides met at the Johan Cruijff Arena in Amsterdam on Sunday.
A win for Ajax, coupled with a defeat for PSV at Heracles, would see them close to within two points of the leaders at the top.
The hosts had Andre Onana to thank for entering half-time with the score at 0-0. The Cameroonian goalkeeper produced an excellent, one-handed reflex save to deny Steven Berghuis goalbound header and what would have been the striker's 12th goal of the campaign.
Ajax were the better of the two teams after half-time and took control of the contest with two goals inside three second-half minutes. The visitors failed to keep out mounting pressure from the hosts, and Donny van de Beek stole in and beat Feyenoord goalkeeper Brad Jones at his near post in the 50th minute.
Three minutes later, and Ajax doubled their lead - Klaas-Jan Huntelaar headed in Joel Veltman's cross from the right. Huntelaar's seventh league goal since he rejoined Ajax ahead of the start of the season from German club Schalke.
Feyenoord's cause was not helped by Nicolai Jorgensen's second yellow card following a late challenge on Veltman, just five minutes after the visitors had fallen two behind.
Ajax were comfortable as they saw out a 2-0 victory - their 14th win in 19 Eredivisie matches this term which moves them to 44 points. But, with PSV having defeated Heracles 2-1 later on Sunday, second-placed Ajax's gap to the leaders remains five points.
Last season's champions Feyenoord remain on 32 points in fifth, after they suffered their fourth loss of the campaign.
