The Terrapins trailed in the fourth quarter, but avoided becoming the Lady Lions' first top five win since 2004 by holding Penn State scoreless in the final nine minutes and finishing on an 18-0 run.
Talvitie's goal helped Finland win its first game of the World Junior Championship.
In addition to Barratt, freshman Aarne Talvitie scored in his World Junior debut against Finland.
Talvitie is the first Nittany Lion to captain his country at the World Junior Championship.
Barratt will be the first player in Penn State hockey history to play for the United States at the World Junior Championship.
The Nittany Lions got off to a hot start shooting the ball but failed to keep pace with the Crimson Tide.