Two goals in as many minutes around the half-hour mark put Vitesse in command and saw them extend their unbeaten run to four league games and six in all competitions.
Vitesse took the lead after 29 minutes when Ricky van Wolfswinkel set up Adnane Tighadouini's third goal of the season.
Two minutes later Van Wolfswinkel doubled Vitesse's lead as ADO were left waiting for an offside flag which never came.
Milot Rashica almost added a third in the second half as ADO failed to produce anything of note.
