The Netherlands only require one point in their final group match to qualify for the finals
Cody Gakpo met Denzel Dumfries' low ball into the box to put the visitors ahead after 13 minutes in Warsaw.
Steven Bergwijn secured victory for Louis van Gaal's unbeaten side with a curling finish on the hour mark.
The Netherlands must avoid defeat against second-placed Belgium in their final fixture to qualify for next summer's Nations League finals.
Belgium remain three points behind the Netherlands after they beat Wales 2-1 on Thursday to maintain their hopes of topping the group.
Van Gaal's side have won four of their five group games and defeated Belgium 4-1 when the sides met in June.
Wales must beat Poland in Cardiff on Sunday to stay in the top flight of the Nations League.
-- Courtesy of BBC Sport