Justin Gant scored 17 points, Manny Arop had 13 and Indiana State beat No. 21 Notre Dame 83-70 on Sunday.
It was the first home November loss for Notre Dame under 14th-year coach Mike Brey, whose teams had been 48-0 in November entering Sunday.
Khristian Smith added 15 points for the Sycamores (2-1).
The Sycamores led 40-30 at halftime, but Notre Dame took a 45-44 lead with 15:07 remaining on Austin Burgett's three-point play. Indiana State responded with an 18-3 run to take control of the game.
Eric Atkins led the Irish with 18 points. Jerian Grant had 17 and Pat Connaughton finished with 16.