Moyer outdueled Brian Birkohfer and Chris Simpson, who combined to make up the top three finishers.
Moyer now has a tour-best 10 victories. He has only raced 11 events.
Two Quincy drivers raced to top-10 finishes. Dustin Griffin was ninth, Denny Woodworth 10th.
Other notable finishers were Brandon Sheppard fourth, Shannon Babb 15th and Brian Shirley 19th.
The six-week tour now hits the home stretch with a race Sunday night in Danville, Ill., before heading to Ohio for its final four crowns. A champ will be crowned Saturday, July 19 in Wauseon, Ohio.
Here are the official points leaders through Saturday night:
1. Shannon Babb, 1,389
2. Ryan Unzicker, 1,375
3. Brian Shirley, 1,317
4. Brandon Sheppard, 1,315