Wall, 28, is averaging 21.3 points and 8.4 assistsfor the 9-14 Wizards.
The Knicks closed the gap to 86-80 at the end of the quarter and pulled within 88-84 early in the fourth. Wall's 20-footer made it 105-89 with 4:24 left, marking Washington's largest lead of the game.
Emmanuel Mudiay's layup pulled NY within 107-97 at the 2:26 mark and Damyean Dotson's 3-pointer made it 107-100 with 1:34 to go.
But Wall hit a 3-pointer with 12 seconds left that mostly ended New York's hopes.
Emmanuel Mudiay had 16 points for the Knicks, and Vonleh had 11.
With New York's franchise star Kristaps Porzingis getting close to free agency, it's imperative that the Knicks pair him with another big-name stud.
Wall's driving layup pushed the lead to 80-69 at the 3:33 mark, but NY rallied to within 86-80 by the end of the quarter.
Good team win for the Wizards.
The Knicks have big plans for the summer when numerous league's top players can become unrestricted free agents.
Markieff Morris continued to play well off the bench with 18 points and 7 rebounds.
NY shot 53.3 percent from the field (23 of 44) compared to 44.4 percent for Washington (20 of 45).
The Washington Wizards are playing improved basketball at the moment, attempting to climb out of the sizable hole dug in the first few weeks of the season. The Knicks would love Kevin Durant, but John Wall might be the closest thing to a star player they could bring to NY.