The race was slowed on the initial start with Croaker moving back a row following a jump call. Adam Sobolik was the new polesitter in the Evil Iron Classics No. 52.
Pierce led the opening trips around the quarter-mile 'Bullring,' and continued to pace the field through a few slowdowns in the mid portion of the 30 lapper.
Jade Hastings stalked Pierce for the lead on each restart, however, even coming within a car length in traffic. Late in the race, Dobmeier joined the lead trio, eventually taking the second spot and setting his sights on Pierce.
Following some troubles to get the 21st lap in the books, Pierce slid off the top of the third turn, then went on to run out of fuel on the restart. Dobmeier was able to pull away from there for his fourth series win of the year.
Nick Omdahl was second in the CMS No. 0, with Jack Croaker third, Brendan Mullen fourth in the Native Nations Cannabis No. 11M, and Laela Eisenschenk fifth in the O'Day Equipment No. 1.
Eisenschenk's run was the third best in series history for a female driver after third place runs for Natalie Sather at River Cities in 2006, and Amber Balcaen at Victory Lane Speedway in Winnipeg in 2014.
The series headed back south for the second time this season, appearing at I-90 Speedway in Hartford, SD.
Troy Schreurs and Aaron Werner led the all-local front row to green at the start. Schreurs led each of the opening 12 laps, as the race went caution free past the midway point.
Sam Henderson lined up to Schreurs outside on the restart, but a wheel stand allowed series regulars Hastings and Mullen to move into second and third.
Hastings reeled in Schreurs in the five laps following the caution, taking the lead on the 18th circuit, roaring around the outside of turn four to take the lead.
Hastings spun in a 360 while a caution flag flew, restarting second to Schreurs. Hastings repeated his pass for the lead in turn four on the restart, with the caution coming out after the pass.
It was all Hastings from there, despite a couple attempts to get lap 22 in the books, as he went on to score his 23rd series win.
Mullen, Schreurs, Ryan Bickett, and Brant O'Banion completed the top five.
The three-race mini-series came to a close on Sunday evening at Casino Speedway in Watertown, SD. For the second time in three nights, Jack Croaker was the polesitter, with Sam Henderson joining him on the front row.
Dobmeier Hastings and quickly joined Croaker as the top trio, but those passes were briefly erased when Ryan Bickett and Laela Eisenschenk got together in turn two.
On the restart, Brendan Mullen moved into third as he and Gage Pulkrabek went three-wide with Hastings in the middle in a battle for the position. Dobmeier and Pulkrabek caught the wall, allowing Mullen and Hastings past.
The NOSA trio of Dobmeier, Hastings, and Mullen lapped in the third through fifth spots, with Mullen taking the lead off the top of turn four at the conclusion of the tenth lap.
Dobmeier followed into second as the leaders worked traffic at the midway point. A caution with 9 to go cleared the way for the leaders, with Dobmeier and trading the top spot on the restart.
This allowed Hastings to close, but the lead duo both got into the wall separately in turn four, with Mullen going for a tumble, ending his hopes.
It was all Dobmeier from there, as he went on to his 180th win over Hastings, who held off a hard charging Justin Jacobsma for second. Jack Croaker and Sam Henderson were fourth and fifth respectively.
NOSA action continues this weekend at Dacotah Speedway in Mandan, ND for the annual running of the Governor's Cup. Hastings will take a 19-point lead over Dobmeier, and 22 over Mullen into the weekend.