In the 358 sprint car feature, Walter Sr., who made a return to the sport just a few weeks ago, led the first 19 laps of the 25-lap feature before Shultz of Carlisle took the lead coming off Turn 2 on lap 19 and went on to score his fourth win the season.
The feature went non-stop with a time of 8 minutes, 12.011 seconds.
"We had some problems here in the last couple of weeks," Shultz said. "We lost the car going for the lead in clean air the other week, but we've been fast. I told my dad I just wanted to get out and lead."
Shultz, who started 11th, moved into the top five on lap 8 and moved into the runner-up spot on lap 18.
"Anytime you win at Selinsgrove is great, but to win four ... we're racing on a shoe-string budget," Shultz added.
Points leader Pat Cannon of Etters finished second with T.J. Stutts third, Walter fourth, and Matt Horst fifth.
Sixth through 10th were Phil Walter, Colby Womer, Scott Wilson, Ryan Kissinger and Duane Mausteller.
Heats for the twenty 358 sprint cars were won by Cannon, Womer and Walter Sr.
For the seventh time this season, Mitch, of McClure, scored the 15-lap pro stock feature win after taking the lead from Sunbury's Jake Buck on the front-stretch on lap 2.
Selinsgrove's Kyle Bachman finished second with Troy Miller, Jim Gerhart and Pete Lauver rounding out the top five. Six through 10th were Nathan Long, Terry Lauver, Brandon Moser, Tommy Slanker, Tom Hartman.
The race was stopped on a lap 7 restart when a nine-car accident occurred in Turn 1 when Tower City driver Shaun Miller (third in points) barrel-rolled his car after his right front tire blew out going into Turn 1. All drivers were OK.
Bob Bussey of Northumberland won the 12-lap roadrunner feature, his fifth of the season.