Rachel Freland made the go-ahead 3 as part of the deciding run in the third quarter that put the Storm (6-1) ahead for good.
Waldorf came back from deficits of 14 and 12 points, but ultimately Simpson's defense -- which forced 27 turnovers -- helped the Storm improve to 3-0 at Cowles Fieldhouse.
Morgan Straight scored 15 points and went 4-for-9 from 3-point range to lead the Warriors (3-5), whose coach faced her former team for the first time. Katie Schutjer (formerly Katie Kitzman) played for Simpson from 2008-10, leading Brian Niemuth's Storm to a pair of Iowa Conference titles and two trips to the NCAA Tournament.
For a while, it looked like the homecoming would be a happy one for Schutjer.
Trailing by as many as 14 in the first half, Waldorf mounted a 17-2 run that started in the second quarter and finished when Kayley Cravens nailed a 3 with 8:08 left in the third for a 38-36 lead. Straight's 3 with 6:41 left in the third put Waldorf ahead 41-38.
Then Simpson's hounding defense took its toll.
The full-court pressure created five turnovers over the next six possessions -- including a 10-second violation -- as the Storm responded with a 14-0 run. Freland nailed the go-ahead 3, Taylor added a trey and Bacon's layup with 3:44 left made it 52-41.
Waldorf pulled within two early in the fourth quarter, but Taylor responded with a 3. A Taylor Fricke layup made it a three-point game, but Kia Rasmussen hit a 3 to push the lead to six. Simpson kept Waldorf at arm's length the rest of the way.
Simpson travels to Concordia-Moorhead on Saturday, Dec. 15. Start time is set for 3 p.m. in Moorhead, Minn.