Peter Bosz's men appeared set for mid-table obscurity earlier in the season, but a significant upturn in their form has got the Arnhem-based outfit aiming to clinch European football.
Zakaria Labyad, currently on loan from Sporting, got Vitesse off to a flyer, netting at the end of a swift breakaway after only five minutes, with Marko Vejinovic adding his side's second 25 minutes from time.
Victory lifts Vitesse to within four points of Feyenoord in third, with leaders PSV up next for Fred Rutten's men on Sunday.
However, it is AZ who remain best placed to challenge Feyenoord, as John van den Brom's side sit just a point behind them thanks to a last-gasp 2-1 win over Cambuur.
Bartholomew Ogbeche appeared to have earned the visitors a share of the spoils with his 62nd-minute equaliser, but Markus Henriksen struck in second-half stoppage time to steal a dramatic win.
Heerenveen secured an emphatic 4-1 triumph at Heracles, Luciano Slagveer netting twice to take his tally up to eight since the turn of the year.
The day's other clash saw Willem II beat rock-bottom Dordrecht 2-1 thanks to a Ben Sahar double.
