Markel Brown scored 28 points and Marcus Smart added 25, as the Oklahoma State men's basketball team snapped Kansas' 18-game winning streak with an 85-80 victory on Saturday at Allen Fieldhouse.
Trailing 83-80 with seven seconds left, KU had one last chance to tie, but point guard Elijah Johnson lost the ball on the dribble and turned it over.
OSU led by as many as 14 in the first half before KU stormed back to take the lead early in the second half.
KU led late before turnovers doomed it down the stretch. The Jayhawks finished with 16 turnovers, compared to 13 for the Cowboys.
Ben McLemore led KU with 23 points on 9-for-17 shooting. Kevin Young added 12 points, while Jeff Withey had 11.
KU (19-2, 7-1 Big 12) will play at TCU at 8 p.m. Wednesday.