Indiana leads Purdue 47-27 at halftime Wednesday at Mackey Arena.
Cody Zeller has 13 points and Christian Watford has 11 for No. 3 IU. A.J. Hammons leads Purdue with nine points.
The Boilermakers trailed 18-17 after Travis Carroll scored with 11:02 remaining in the half.
The Hoosiers scored the next nine points. Jeremy Hollowell and Remy Abell made shots to start the run. Will Sheehey then stole the ball and finished with a dunk. Victor Oladipo capped the run with a three-pointer.
Derek Elston made two free throws to extend the lead to 34-20 with 5:40 to go.
Hammons got the Boilermakers back into the game. His dunk with 4:34 remaining brought Purdue within 34-25.
Hammons picked up his third foul with 4:18 remaining. Indiana then scored the next 13 points.
IU went 16 of 17 from the foul line in the half. Purdue shot 36.4 percent from the floor.