Seth Hinrich and Jim Mower tallied 14 points each and Lafayette held off a late surge to beat Penn State 61-57 on Wednesday night.
Nick Petkovick added 13 points off the bench for the Leopards (4-5), who hit nine 3's and stymied Penn State's offense.
The Leopards led by as many as 10 in the second.
The Nittany Lions (6-4) shot just 33 percent (19 of 58) including a 3-of-23 performance (13 percent) from 3-point range.
Jermaine Marshall tallied 20 points for Penn State, which lost its first-ever game against a Patriot League team. The Nittany Lions are now 1-25 against the conference.
Tim Frazier, who entered the game as the Big Ten's leading scorer at 19.2 points per game, scored just three points against Lafayette, and was 0 of 12 from the field.
Lafayette used a 2-3 zone defense to slow down Frazier, Penn State's lone returning starter.
''When you start missing some shots it gets in your head sometimes,'' Penn State coach Pat Chambers said. ''But give Lafayette a lot of credit. A great game plan.''
Petkovich's 3 with 10:35 remaining in the first half put the Leopards ahead 17-16 -- a lead they would never relinquish.
Lafayette built a 10 point lead midway through the second, but a 3 by Marshall with 2:12 remaining brought Penn State within three.
Down 59-56, Frazier went to the line with 10.4 seconds left after Lafayette coach O'Hanlon called a timeout he didn't have. Frazier made one of two technicals and the Leopards sealed it from there with free throws.
''We did what we needed to do at the end of the game,'' O'Hanlon said. ''It was one of the uglier finishes to the game, but I thought our guys really stepped up.''
The Nittany Lions outrebounded Lafayette 47-26, but 13 turnovers added to their offensive woes.
''We made too many mistakes,'' Chambers said.
After a 72-70 loss to Mississippi on Sunday, Penn State has lost back-to-back games for the first time this season.
Chambers did not make players available to the media after the game.
