Four late free throw conversions by Malik Smith in the final 30 seconds and one by Elliott Eliason with 33 seconds, enabled the Gophers (13-3, 2-1 Big Ten) to hang on after taking its first lead of the second half with 1:43 remaining.
Tim Frazier scored 20 points for Penn State (9-7, 0-3) but was unable to finish the game after injuring his right leg with 2:08 left and Penn State leading 59-57.
Mathieu forced back-to-back Penn State turnovers, including a strip of John Johnson and his ensuing basket gave the Gophers a 63-60 lead and forced Penn State to foul.
The Nittany Lions' Allen Roberts missed a game-tying 3-point shot with 1 second to go.
Minnesota, which has won 30 out of 40 games in its series with Penn State, also got 11 points and 12 rebounds from Eliason.
Gophers Headed to Vancouver in November 2018
Minnesota will be among an eight-team field in the inaugural Vancouver Showcase next year.
Men's Basketball B1G Schedule Announced
Gophers will play every day of the week during the conference season leading up to Big Ten Tournament in NYC.
Men's Basketball Announces Non-Conference Schedule
Featuring 10 home games along with a challenging slate of opponents, the Minnesota men’s basketball team unveiled its non-conference schedule Tuesday.