For one of the highest scoring teams in the American Rivers Conference, it was defense that paved the way for Simpson's second-straight win.
Kyle Wagner scored 12 points and Ben Rajewski added 10 for the Storm (6-2, 2-1), who held Buena Vista under 10 3-pointers for the first time this season. Coming into the game averaging better than 13 per game, Buena Vista managed just 8-for-26 from long range.
Simpson led 59-57 with just under 6 minutes to play before putting the game away with a 13-2 run.
Reiter started the rally with a layup and a pair of free throws before Wagner nailed a deep 3 from the left wing to make it 66-57. A Robert Hawkins jumper slowed the run momentarily, but Reiter added two more free throws and a layup. Rajewski's jumper with 2:16 left gave Simpson a 72-59 lead.
The lead remained in double figures as the Storm snapped a five-game losing streak to the Beavers (3-3, 1-1).
Hawkins scored 18 points for Buena Vista, which shot just 3-for-14 from 3-point range in the second half.
After giving up an average of 86.2 points over the first six games, Simpson has held its last two opponents under 70.
Simpson led by seven late in the first half, but the Beavers fought back. A short jumper by Alex Rogers, Jr. with 1 second left capped a 7-0 run and made it 35-35 at halftime.
Simpson hosts Faith Baptist in the final home game of 2018 on Saturday, Dec. 8. Tipoff is set for 4 p.m.