Daley Blind and Hakim Ziyech scored hat tricks as Ajax dismantled bottom of the table De Graafschap 8-0 on Sunday.
Former United player Blind and Morocco midfielder Ziyech ran riot after De Graafschap's Daryl van Mieghem had failed to take a one-on-one chance in the opening stages.
Dusan Tadic was set up by Ziyech to open the scoring before Nasser Mazraoui and Ziyech made it 3-0 soon after the half-hour.
Ziyech added a 62nd-minute goal before Blind got into the act with a long-range strike.
Ziyech completed his treble, but Blind was far from finished, scoring another to make it 7-0 and adding the eighth and final goal to round off his hat trick.
It came after the 28-year-old scored four Premier League goals in four seasons at United, and only three Eredivisie goals in his first six-year spell at Ajax.
Ajax remain within two points of leaders PSV Eindhoven.