Tim Frazier hit a floater in the lane with 8 seconds left and Jermaine Marshall blocked Sam Maniscalco's layup at the buzzer to give Penn State a 54-52 upset of No. 22 Illinois on Thursday night.
Frazier finished with 12 points and nine assists for the Nittany Lions (10-10, 2-5 Big Ten), who ended a 3-game losing skid.
Off a timeout, Frazier drove at the top of the key before Jon Graham's pick freed him from hounding defender Brandon Paul.
The Illini (15-4, 4-2) lost for the first time since re-entering the AP Top 25 this week. They had a short stay atop the Big Ten as the league's lone one-loss team in conference play.
Paul had 20 points to pace the Illini, while Meyers Leonard added 15.
NCAA Top-25 Men's Basketball
#4 Duke Blue Devils 91, Wake Forest Demon Deacons 73
#8 North Carolina Tar Heels 82, Virginia Tech Hokies 68
#17 Virginia Cavaliers 70, Georgia Tech Yellow Jackets 38
#23 Saint Mary's Gaels 61, Pepperdine Waves 47
Penn State Nittany Lions 54, #25 Illinois Fighting Illini 52