Nowitzki made consecutive 3-pointers Tuesday night against Washington to reach 25,194 points, two ahead of West.
The 11-time All-Star and 2007 MVP was struggling from the field before a loose ball bounced to him above the key. He grabbed it, turned and hit a shot to get within a point of West's record.
On Dallas' next possession, Gal Mekel passed to Nowitzki a few feet left of the previous spot, and Nowitzki pulled up and hit another from long range. The bucket that put him ahead of West gave him 16 points for the game.
Reggie Miller is 15th on the scoring list with 25,279 points.