Schatz, from Fargo, N.D., took the lead on the 13th of 50 laps with a pass on the bottom of the track and held on to take the $150,000 winner's check.
Craig Dollansky was third, followed by Kraig Kinser and Jason Meyers.
Steve Kinser, Kraig's father, failed to qualify for a Nationals championship feature for the first time since 1977. Steve Kinser has a record 12 Nationals titles, spanning three decades.
Former champions Danny Lasoski, Sammy Swindell and Tim Shaffer also missed the A-main.
Copyright 2012 by The Associated Press