Demy de Zeeuw put Ajax on track midway through the first half and Marko Pantelic added a second when he netted a rebound after Luis Suarez had hit the post. Dennis Rommedahl scored the third 15 minutes before time.
PSV Eindhoven, 2-0 winners over ADO Den Haag on Saturday, are top with 58 points after 22 matches, three points clear of Twente. Mexican Francisco Rodriguez opened the scoring after 16 minutes when he nodded in a corner from Balazs Dzsudzsak at the near post and Ola Toivonen netted a rebound after the break to make sure of victory.
Ajax remain third on 49, seven more than Feyenoord who lost for the first time since Nov. 1 losing 2-1 at home to AZ Alkmaar.
Mounir El Hamdaoui opened the scoring for Alkmaar from close range after 28 minutes but an own goal from Pontus Wernbloom brought Feyenoord level before the interval.
In a lively second half, both teams had their chances to clinch the match but three minutes before time Mexican Hector Moreno headed home Alkmaar's winner from a Stijn Schaars corner.
Fifth-placed Heracles Almelo fought back from two goals down to beat nine-man Groningen 4-3.
Groningen went 3-1 up thanks to two goals from Thomas Enevoldsen and one by Morten Nordstrand but red cards for Gibril Sankoh and Leandro Bacuna early in the second half gave Heracles hope.
Bas Dost grabbed his second goal of the match for the home team in the 72nd minute before Willy Overtoom levelled and Birger Maertens scored the winner with a minute left.
Elsewhere, Heerenveen beat Utrecht 2-0 and Roda JC Kerkrade overcame Sparta Rotterdam 2-1.
