Illini guard Kendrick Nunn scored 19 points, and Illinois held Penn State to three points in the last 9:44 of a 60-55 win in the Bryce Jordan Center on Sunday.
Illinois snapped an eight-game losing streak, winning for the first time since defeating the Nittany Lions 75-55 in Champaign on Jan. 4.
"I'm really proud of our guys for the way that they fought tonight and throughout, to be honest with you," Illinois coach John Groce said. "I'll be honest with you, I was just as proud of them last week."
The Nittany Lions went nearly nine minutes without a point until guard D.J. Newbill connected on a free throw with 51 seconds left to draw Penn State within 54-53.
Nunn hit a 3-pointer from the right corner with 22 seconds left, and Newbill answered with a layup to make it 57-55 with 14.7 seconds remaining.
Illini guard Tracy Abrams connected on two free throws, and Penn State guard Tim Frazier missed a 3-point try with five seconds left.
Penn State led 52-49 prior to its late drought.
Illinois (14-10, 3-8 Big Ten) got 11 points from guard Malcolm Hill and nine points from guard Rayvonte Rice, the team's leading scorer who was held without a point in the first half.
"When he touched the ball, it felt like the whole arena was guarding him," Groce said of Rice, who finished 2-for-8 from the field. "But he handled it very maturely."
Illinois shot a modest 38.8 percent from the field and 31.8 percent from 3-point range. The Fighting Illini took care of the ball, committing only six turnovers, and overcame struggles at the free-throw line, where it went 4-for-11 in the second half.
However, Illinois' defense, particularly during the stretch run, clinched the victory.
"When we needed our defense the most, we were able to affect them at a certain level," Groce said.
The Nittany Lions, who shot 38.2 percent overall and 27.8 percent from 3-point range, got 19 points from Newbill and 11 from Frazier. Penn State (12-12, 3-8) missed eight shots from the field between Newbill's jumper with 9:44 left and his drive with 16 seconds to play.
"We needed to continue to keep attacking," Frazier said. "If we can't score, we need to be able to defend and get rebounds."
There were nine lead changes in the first nine minutes of the second half, which began with a 31-31 tie. The first half had a similar back-and-forth vibe.
The Fighting Illini, who got eight first-half points from Nunn, used a 10-2 run to take a 31-22 lead on Nunn's 3-pointer with 3:25 left before the Nittany Lions scored the final nine points of the half on a 3-pointer by Newbill and six points from Frazier.
Newbill, who was ejected from the first matchup of the season against Illinois, made four of six shots from the field prior to halftime, and he finished seven of 12. Forward Donovon Jack had eight first-half points.
Penn State committed just six turnovers in the game as well, and Illinois had just one point off turnovers, but some poor shot selection by the Nittany Lions and an Illini defense that contested nearly every shot made it a moot point.
"I thought we took a couple ill-advised 3s late in the game, when I'd like us to take it in inside or drive it," Penn State coach Patrick Chambers said. "Their defense was terrific on Tim and D.J. toward the end. ... They made the winning plays.
"That was a desperate team we played. That was a flat-out battle."
NOTES: Illinois won for just the second time in its past six visits to State College. ... Penn State senior G Tim Frazier broke Freddie Barnes' school career record for assists when he posted his 601st in the second half. ... Penn State junior F Ross Travis returned to the starting lineup Sunday after coming off the bench in each of the previous four games. Travis started the Nittany Lions' first 19 games before being replaced by freshman G Graham Woodward.