Anthony Roy drilled three 3-pointers during a key two-minute stretch to help Oklahoma State earn an 86-81 victory over Northwestern on Thursday night as part of the Thanksgiving Classic doubleheader in Chicago.Roy, a high-scoring Green Bay transfer making his first start for the Cowboys (7-0), scored all 16 of his points in the second half. Oklahoma State’s Jaylen Curry produced 16 of his 18 points in the first half, while Vyctorius Miller added 17 points.Nick Martinelli paced Northwestern (5-2) with a season-high 28 points on 12-of-16 shooting while grabbing 10 rebounds. Angelo Ciaravino added a season-high 14 points while Arrinten Page worked through first-half foul woes to post 11 points and seven rebounds.After a tight first half, the teams started the second half by exchanging mini-runs. The Wildcats went on a 6-0 spree to take a six-point lead before the Cowboys reeled off eight in a row with help from a flagrant foul committed by Jayden Reid. Shortly after he went to the bench, Northwestern scored seven straight to restore a 53-48 margin.When the Cowboys’ Kanye Clary fed Parsa Fallah an inbounds pass for a layup to cap a 10-0 run, Oklahoma State claimed a 64-58 lead with 7:27 to play. Though the Wildcats broke the spell at that point, Roy hit a pair of rainbow 3-pointers from the top of the key to keep the Cowboys in front.The Wildcats got as close as 80-79 on Martinelli’s second-chance three-point play with 34.2 seconds left, but Reid airballed a 3-point attempt to tie with 22 ticks remaining. The Cowboys went 6-for-6 at the line in the final 31 seconds.