The Storm (18-12, 5-3 Iowa Conference) trailed in each game but came up with clutch plays when they needed them most to snap a four-game losing streak in the series.
Down 3-1 in the third inning of the opener, Jensen evened the score with a two-out, two-RBI single to left. Jensen - who doubled in the fifth - then broke the 3-3 tie with a liner off the left field wall in the bottom of the seventh. Tori Haag scored from third on the play after leading off the inning with a double.
Haag went 2-for-3 with two runs socred and Van Vleet earned the win in relief of Kaytlyn Ernst, holding Dubuque hitless over the final two innings.
The Spartans (17-11, 4-4) led 4-3 in the sixth inning of game two before Simpson scored two on a throwing error and Hillary Harmon drove in a third run for a 6-4 Storm lead.
Getting the start in game two, Van Vleet (12-2) retired the final three batters after surrendering a leadoff single in the seventh for the complete-game win. She allowed three earned runs and struck out three.
Van Vleet went 3-for-4 to lead Simpson at the plate and Jensen drove in two on a double in the second.
Dubuque built an early 3-0 lead on a two-RBI single by Tori Woltz in the first and a solo homer by Ainsley Billesbach in the second. Emma Negrete drew a bases-loaded walk and Jensen's double tied it 3-3 in the second.
Van Vleet got plenty of help from heads up plays by veteran infielders Kylie Van Houten and Britney Steele. Van Houten started a rundown between third and home in the third inning to put out the runner at third. Steele alertly went home on a ground ball with runners at first and third in the fifth, allowing Haag to tag out the runner before reaching the plate.
Simpson gets a break from Iowa Conference play on Tuesday, April 15 when it hosts Westminster (Mo.) in a doubleheader beginning at 3:00 p.m. Out of Fulton, Mo., the Blue Jays are 11-15 overall and 8-6 in the St. Louis Intercollegiate Athletic Conference.