The Boilermakers never trailed in the extra period, but Ostarello’s basket with 43 seconds left made it 68-66 Purdue.
Courtney Moses and Drey Mingo also scored 17 points for Purdue (13-2, 2-0 Big Ten) in another close one between the schools. All three games between them have gone to overtime.
Purdue beat Illinois 67-66 in overtime Wednesday in its Big 10 opener.
Lindsey Moore led all scorers with 22 points for the Huskers (11-4, 1-1). Moore also had eight assists and Jordan Hooper had 15 points and 14 rebounds for Nebraska, which had won its last five.
The schools met twice last season. Nebraska, new to the Big Ten, won the regular-season meeting at Purdue in triple overtime, but Purdue won the tournament championship in double overtime at Indianapolis.