Winnebago sent Byron home with its first postseason loss in three years after a 53-44 win in the regional final.
Senior Malia Shank scored a career-high 17 points.
"We know they're a good team, said Shank. "We knew we had to come out strong. We struggled a lot throughout the season with injuries, but I think we proved our spot. We didn't get the injury card. We worked hard. It feels good."
Senior Kiah Garrigan added eight points, 14 rebounds and four steals.
"I'm speechless," said Garrigan. "I don't even have words for it. It feels so good to have the energy and come out and finally win the game that we deserved. It's so fun doing it with my best friends out here and I wouldn't want to be without anyone else on the court."
The Indians will play in the Bureau Valley Sectional semifinal on Monday against Spring Valley Hall.