The Hoosiers (24-23 overall, 1-6 Big Ten) relinquished a 2-0 lead earlier in the game but held Wisconsin at bay in the extra innings.
After a pair of fly outs opened the ninth, Indiana sophomore outfielder Lauren Hines doubled to left center. One batter later, senior Val White singled to center field, scoring freshman pinch runner Kim Richards from second.
The Badgers threatened in the bottom of the ninth when junior designated player Anastasia Miller hit a 1-one double. Indiana sophomore pitcher Mariangee Bogado, though, struck out Wisconsin freshman second baseman Tara Hamilton. Sophomore first baseman Kaitlin Reiss then hit a ground ball to short stop and Miller was called out after bumping into Indiana freshman shortstop Meghan Connors.
The Badgers (23-20, 3-6) came close to winning the game in the bottom of the seventh as senior left fielder Diana Consolmagno doubled off the top of the fence with two away, but was left stranded, sending the game to extra innings.
Wisconsin wasted another great chance to win it in the bottom of the eighth, loading the bases with only one out. However, Bogado got the job done again against UW's top two hitters. Zacher grounded to short for a force out at the plate and Gillette struck out on three straight pitches to send the game to the ninth.
All told Wisconsin left 15 runners on base.
Bogado (13-13) pitched five innings in relief for Indiana to claim the win. Freshman Eden Brock (10-8) pitched 8 2/3 for Wisconsin, allowing two earned runs on seven hits.