It's Iowa's first home loss of the season.
The Hoosiers (9-6) were led by 23 points from sophomore Trayce Jackson-Davis, while John R. Wooden Award front-runner Luka Garza posted 28 points and 12 boards in a losing effort for the 12-3 Hawkeyes.
Garza recorded his 49th career 20-point game, the most by a Big Ten player over the last 25 seasons.
Guard Rob Phinisee chipped in with 18 points on 4-of-7 shooting from behind the arc for the Hoosiers.
It was a defensively sound display from Archie Miller's team, with Indiana holding a high-octane Iowa squad to no field goals made over a nine-minute spell in the second half.
The road victory against a marquee opponent should help the Hoosiers' claims to an at-large bid. Indiana hosts conference foe Rutgers on Sunday and will look to move to 5-4 in the Big Ten standings.