And it came on a night the fifth-seeded Cowgirls lost star point guard Tiffany Bias for nearly 10 minutes in the second half with what appeared to be a left leg or foot injury.
Fourth-seed Purdue (22-9) was led by Whitney Bays with 21 points and 13 rebounds.
After Bias left, Purdue closed to 52-46, but the Cowgirls regained control with a 9-4 run and never let Purdue get close.
Beating Purdue on its home court, where the Boilermakers are now 20-8 all-time in NCAA tournament games, was a huge step for a program that lost its head coach and an assistant coach in a fatal plane crash 2½ year ago.
Since then, Oklahoma State has made steady progress — winning the 2012 WNIT title, taking a double-digit lead in the second half of last year’s second round game before losing at Duke and now finally returning to the NCAA regionals.
The Boilermakers, meanwhile, have lost four straight second-round games — three straight to No. 5 seeds with two of those coming at Mackey Arena. Senior guard Courtney Moses scored 11 points in her final game but did make two 3-pointers to break Katie Gearlds’ career record. Moses, who entered the game tied with Gearlds at 238, finished with 240.