At that point, Rahmer trailed Cannon by more than two seconds.
He was on a mission.
"I really wanted to win this race," he said. "I was hitting my marks about 80 percent of the time and just couldn't get past those lapped cars."
By lap 33, Rahmer was cutting into Cannon's lead and he got it down to under a second by lap 38.
"I had to slow down at the end for the lapped car and that's when I saw Fred's nose," Cannon said. "You can race guys like Fred and Lance very clean."
Rahmer got as close as two car lengths on lap 41, but that would be as close as he got over the final three laps.
Finishing behind Cannon and Rahmer was Dewease with Greg Hodnett and Stevie Smith rounding out the top five.
Sixth through 10th were Aaron Ott, Brent Marks, Chad Layton, Mike Erdley and Steve Buckwalter.
Heats for the 30 410 sprint cars were won by Dietrich, Brian Leppo and Rahmer.
Hodnett was the first driver to break into the 16-second bracket in qualifying, the latter coming in the 1998 Open.
Layton won the B-Main in a non-stop, 10-lap track record of 2 minutes, 48.95-seconds.
The 410 sprint cars will have one final race at Selinsgrove on Sunday, Oct. 4, a Twin-20s program. The date will not be used if Williams Grove has to use it for a rain date for the World of Outlaws-sanctioned National Open.
The first 24 laps went non-stop as Cannon lead Brian Leppo at the break by 1.6 seconds. Cannon jumped out to the lead at the start from his outside pole position with Leppo following closely in second.
Some of the top 410 sprint car drivers in the world were weaving in and out of lapped traffic by lap 7.
Greg Hodnett, who set fast time in time trials, moved into fifth on lap 7, getting by Rahmer who had run in the top-five for six circuits. Hodnett and Rahmer then swapped the position back and forth for several laps.