But then the Nittany Lions (9-10 overall, 3-7 in the conference) launched their comeback, outscoring the Hawks, 23-6, down the stretch.
A layup by junior guard Paul Murphy, who scored 14 points on 7-for-12 shooting, put Penn State ahead for good, 55-54, with 1:04 remaining. Freshman guard Brian Allen followed with four straight free throws to ice the game.
The Hawks (14-4, 8-2) were outscored, 31-19, in the second half and shot just 29 percent (6-for-21) from the field after going 15-for-27 in the first half.
Penn State, in contrast, shot 67 percent (12-for-18) in the second half and hit seven of nine free throws after connecting on just two of seven in the first half.
The Nittany Lions were led by Murphy and Carl Chrabascz with 14 points apiece. Allen was the only other double-figure scorer with 10.
Maurice Martin led St. Joe's with 17 points and a game-high 12 rebounds. But Martin shot 5-for-16 from the floor. Wayne Williams, often a catalyst for the Hawks, shot 1-for-6. Rodney Blake, who sat out seven minutes of the second half with four fouls, had 13 points but only three rebounds.
The loss ended St. Joe's five-game winning streak and stopped Penn State's six-game conference losing streak.