Purdue led for less than three minutes overall and rallied from six points down in the final 3 1/2 minutes. Ivey scored eight points during the decisive stretch.
After Ivey’s go-ahead 3-pointer, Purdue fouled Washington to prevent the Buckeyes from attempting the tying 3. Washington made the first free throw, missed the second and Aaron Wheeler secured the rebound for the Boilermakers.
Purdue dominated inside, outscoring Ohio State 36-8 in the paint and holding a 38-30 rebounding advantage. The Buckeyes went 6 for 18 on 2-point attempts.
Purdue hosts No. 7 Michigan on Friday.
Ohio State visits No. 10 Wisconsin on Saturday.