Siem de Jong struck a hat-trick as champions Ajax moved three points clear at the top of the Eredivisie table with a thumping win at 10-man Heerenveen.

Ajax cashed in fully after Heerenveen goalkeeper Brian Vandenbussche saw red after just three minutes for hauling down De Jong.

Theo Janssen converted the spot kick and, after Ismail Aissati scored the second, De Jong bagged his hat-trick to seal a ninth successive league win.

It was also a fifth clean sheet on the spin for Ajax as their lead at the top grew thanks to a 2-2 draw between closest rivals AZ Alkmaar and FC Twente.

Heerenveen's chances of stopping Ajax's charge to the title were already slim before they lost Vandenbussche after just three minutes.

De Jong was fouled and Janssen beat replacement goalkeeper Kristoffer Nordfeldt to send Ajax on their way.

It was 2-0 on 19 minutes when Aissati blasted in from an acute angle after sought-after midfielder Christian Eriksen picked him out.

De Jong then took over with two goals before the break. His first on 25 minutes was the most memorable as he drilled home an unstoppable drive from 18 yards after Eriksen again provided the pass.

The Denmark international supplied his third assist in injury time to set-up De Jong for his second goal, with his shot slipping through the legs of Nordfeldt.

De Jong completed his hat-trick on 63 minutes when Nordfeldt completely missed Daley Blind's cross to allow the striker the easiest of his three goals.

The Holland international was denied a fourth by the woodwork when he headed an Aissati cross against the frame of the goal, with Kolbeinn Sigthorsson then heading against the crossbar as Ajax eased to another win.