The Knicks were particularly effective from beyond the arc, where they connected on 18 of 33. Novak paced five players in double figures for New York.
Led by Carmelo Anthony, who finished with 17 points, the Knicks took a 38-21 first-quarter lead.
But the young Wizards answered the challenge. Reserve Bradley Beal scored all of his 12 points in the Wizards' 22-0 run that gave them a 56-53 halftime lead.
Novak hit consecutive 3s to put the Knicks up 95-88 with 6:28 left.
Jordan Crawford led the Wizards with 17 points.