Eckert paced the first 13 laps of the race before Lanigan, who started fourth, closed on Eckert and made the winning pass on the outside of Turn 2 on lap 14.
"Our car was good, I was just waiting for Rick to bobble a bit and, when he did, he gave me the top side and that's how we made the pass," Lanigan said. "Selinsgrove has to rank in the top five for tracks that we race on for speed."
Lanigan raced to a straightaway by lap 40 when Eckert started to close as Lanigan was dealing with lapped traffic
"We went a bit soft on tires and we just keep coming up short," said Eckert, who finished 2.8 seconds behind Lanigan.
"It was great to race in front of the hometown fans this weekend and I hope they keep having us back."
Cochran, who is sixth in Selinsgrove Speedway late model points, passed two-time series champion Richards for third on lap 48.
"I couldn't believe we were going this far forward," Cochran said. "This weekend gives us confidence to test the waters and maybe head to Charlotte (WoO World Finals in November) and maybe run with (WoO LMS) for some races next year."
Richards settled for fourth, while Shane Clanton was fifth.
Sixth through 10th were Stone, Saturday's winner Gregg Satterlee, Tim McCreadie, Morgan Bagley and Jeff Rine.
Heat wins for the 36 late models went to Clanton, McCreadie, Coleby Frye and Lanigan. Twin B-Mains were won by Rine and Dylan Yoder, while Clanton set fast time with a lap of 19.244 seconds.
In the 20-lap limited late model feature, Dover's Gene Knaub, who started fourth, scored his 16th of the year in a non-stop race. Knaub raced a street stock at the speedway more than 15 years ago.
Chade Myers was second, with Denny Bonebrake, Robbie Black and J.R. Rodriguez rounding out the top five.
Sixth through 10th were Tommy Slanker, Travis Mease, Matt Nailor, Luke Hoffman and Eric Irvin.
Heats for the 23 limited late models were won by Rodriguez, Knaub and Jake Jones.