The Hoosiers took the lead with 4:42 left in the second quarter off a rushing touchdown from junior running back Stephen Houston and held on for the rest of the game.
The 31-17 victory at Illinois (2-6, 0-4) marks the Hoosiers (3-5, 1-3) first Big Ten win of the season.
Also, this is IU's first road victory since the win against Purdue in the 2010 Old Oaken Bucket game.
Sophomore quarterback Cameron Coffman started the game for the Hoosiers, but was replaced with two minutes left in the first quarter by freshman Nate Sudfeld.
Sudfeld was not substituted the rest of the game and ended up completing 10 of 15 passes for 107 yards and two touchdowns.
Eight different receivers caught a pass or more from the two quarterbacks.
Houston compiled 21 of the Hoosiers' 31 points.
The Little Rock, Ark., native recorded 73 rushing yards for two touchdowns and 16 receiving yards for one touchdown.
The Hoosier defense gave up two touchdowns in the first half, but then held the Illinois offense to only a field goal in the second half.
Junior safety Greg Heban led the team with 13 tackles and even recovered the ball off a muffed punt on special teams with 6:11 left in the second quarter.
The win gives IU Coach Kevin Wilson his first Big Ten victory of his career.
Next week, the Hoosiers return home to face Iowa (4-4, 2-2) at Memorial Stadium.
