Penn State (10-19, 2-15 Big Ten), last in the 12-team conference, scored the game's first 12 points, withstood a Northwestern surge, then pulled away in the second half. The Nittany Lions' only other conference win was at home against No. 7 Michigan on Feb. 27.
Northwestern (13-17, 4-13) has lost seven in a row.
Northwestern's Alex Marcotullio, who scored a career-high 22 points, put the Wildcats ahead 54-53 with a 3-pointer with 6:13 to play. But Penn State scored the next six points, beginning with Sasa Borovnjak's short jumper, and scored 13 of the game's last 18 points. Borovnjak had 15 points and 10 rebounds.
Reggie Hearn, who scored 11 points before fouling out with 3:07 to play, was the only other Northwestern player in double figures.
Missouri State downs SIU in MVC Tournament
ST. LOUIS (AP) Marcus Marshall scored 18 points and Anthony Downing had 16 as Missouri State defeated Southern Illinois 61-53 Thursday night in the opening round of the Missouri Valley Conference tournament.
Christian Kirk added 10 points and eight rebounds for the seventh-seeded Bears (11-21), who will face No. 2 seed Wichita State on Friday.
Desmar Jackson and Anthony Beane Jr. scored 12 points apiece for 10th-seeded Southern Illinois (14-17). The Salukis had won six of their last eight games after starting the conference season 1-10.
Missouri State used an early 15-2 run to go on top 23-15, and led 32-22 at halftime. After the Salukis pulled within five points midway through the second half, the Bears scored eight straight to go ahead 47-34 and led by double digits the rest of the way.
Missouri State hit 16 of 22 free throws to just 6 of 10 for Southern Illinois.
Drake knocks Bradley out of MVC Tourney
ST. LOUIS (AP) Chris Hines scored 16 points and Drake defeated Bradley 81-66 Thursday in the opener of the Missouri Valley Conference tournament.
The ninth-seeded Bulldogs (15-16) earned a quarterfinal game against regular-season champion Creighton on Friday.
Joey King scored 15 and Gary Ricks added 14 points for Drake. The Bulldogs led by as many as 17 points in the first half, though the Braves scored the last eight of the half to cut Drake's lead at the break to 41-32.
Bradley (16-16) got within three with 6 1/2 minutes left, but Drake went on a 13-0 run to put it out of reach.
Jake Eastman had 15 points and eight rebounds for the eighth-seeded Braves. Will Egolf also scored 15 points, Walt Lemon Jr. scored 14 and Tyshon Pickett added 11 for Bradley, which improved nine games from last season's 7-25 finish.