In the 13th inning, Dylan Burdeaux tripled home Zac Shepherd before coming home to score himself on a Cameron Warner single.
Pitcher Evan Hill then came on in the bottom of the 13th to pick up the save for West Michigan.
Overall, Derek Hill, Danny Woodrow, Cole Bauml, Burdeaux, and Warner all led West Michigan with two hits each.
West Michigan is 66-29 overall on the season and 21-7 in the second half. The Whitecaps are three games ahead of Fort Wayne for first place in the second half Midwest League Eastern Division standings.
West Michigan will close out its series in Wisconsin on Monday at 1:05 p.m.